Fleet Composition and Final Thoughts
I've been arguing for a defensive play style for the TEC Loyalists and then a late-game, large fleet push fuelled by a powerhouse economy. I've reasoned that coupled with a heavy emphasis on culture and combining the Ankylon with massed capital ships the TEC Loyalists can build an irresistible pressure against a foe and wear down opposition over time. There's a few things I've mentioned and want to reiterate and some other things that I want to make explicit that may have only been implied up till now.
First, any strategy in Sins is founded upon aggressive early expansion. There are a lot of other threads that can help a new player learn how to expand rapidly in the very early game, I won't go into details. I just want to point out that a defensive mid-game strategy is still built on an opportunistic and aggressive start. I say opportunistic because either of the TEC factions are arguably the best 'rushers' in the game; if a situation allows for crippling or destroying an enemy in the early game it's foolish not to take advantage.
Second, defensive does not mean passive. Two separate points to make here regarding scouting and titan/capital levelling.
The Arcova Scout Frigate with Sensor Drones researched is arguably the best scout ship in the game. There is no excuse for not having every bordering enemy world under constant surveillance. Frankly, in the late game the Arcova is cheap enough that building 5-10 of them and trying to get one of them through to the next enemy world and get a sensor drone on it is a good idea where you can. You should always know where the enemy fleet is and what its composition is well before any attack could be launched against your border. Your own fleet should always be present if/when an enemy jumps into one of your border systems, there is no excuse for being caught with your ships somewhere else.
If you are playing against the AI, no matter what, it will attack from time to time, allowing your Titan and ships to gain experience. A human player may be more cautious if you've built up your defences well and do a good job of keeping your fleet opposite his. The Akkan's Ceasefire ability allows you to attack, do some damage, and retreat. Use this to raid and gain experience, especially for the Ankylon. Ogrov Torpedo Cruisers are great for raiding. They do massive damage to structures, they have a huge range to start with and when paired with an Akkan they are ridiculous. Jump in with the Ankylon, the Akkan, the Ogrovs, and a bunch of Gardas, let the Ogrovs rapidly tear some things down while the Gardas tear up the inevitable immediate strikecraft response and then Ceasefire and leave before the enemy fleet can effectively react. You could send some Percheron Light Carriers, too, loaded with fighters. Strikecraft aren't worth much experience individually, but if you can kill a bunch of them it adds up. Try to raid systems the enemy Titan isn't in, so that any losses you suffer don't help it level up! Don't worry if it's one jump away, you'll be gone before it can join the fight.
Third, the purpose of playing defensively is to hold the enemy at bay while you first build up your economy and then out-research your opponent. If you allow the enemy to also build up his economy and conduct unlimited research, you're just wasting time as he will probably maintain parity.
As discussed before, build the economy up with dual starbases with trade facilities so that the logistic slots on your border can be given over to Broadcast Centers. Force your opponent, who has less logistic slots to work with and can only build trade facilities on one starbase/gravity well and can't conduct production of frigates and cruisers on his starbases (unless he's also a TEC faction, of course), to spend precious logistic slots countering your culture.
Research and build multiple Novalith Cannons and keep bombarding all of the enemy's planets: you don't have to wipe the planet out, though it's nice if you do. The purpose is to keep applying the max population and trade debuff and cripple your opponent's credit income.
If you have excess mineral or crystal income, keep selling to the Black Market to keep the market crashed. If you cripple the enemy credit income, he'll have to sell resources for credits, and the lower you can keep the market price, the worse off he'll be.
Keep raiding and inflicting damage that your enemy has to rebuild or retrain. With judicious use of Ceasefire you should be able to inflict more losses than you take. Even if losses are even, your economy should be able to handle the cost of replacement easily, while his will be further drained.
Fourth, if you use all of the available capital ship crew (and, as much as I think massed capitals are the way for TEC Loyalists, I'm not sure there's a need to train ALL that you can) you will use a little less than half of the maximum fleet supply. With the TEC Loyalist economy, you should be able to afford to max out your fleet supply research and you should always be using all that you have researched. In other words, you are going to have a LOT of frigates/cruisers.
Some ships are ones that you will always want to have in numbers:
Cielo Command Cruisers with Designate Target make killing big scary enemy ships a lot easier by increasing their damage taken (before mitigation) by 40%. Don't underestimate the usefulness of Embolden, either, as it decreases weapon cooldown and restores shields. The shield restore rate isn't that impressive, but the weapon cooldown buff increases DPS output and anything that increases DPS for TEC fleets is good. I try to keep 10-20 of these ships around.
Hoshiko Robotics Cruisers greatly enhance the durability of TEC fleets in the early-mid game. They aren't quite as necessary for that role after you've done your hull and armor research, but they fortunately gain an ability to shut down the weapons and movement of enemy frigates and cruisers. Each Hoshiko can use Demolition Bots to keep two ships shut down. There are two things to note, if you are using your Hoshikos for the Demo Bots, turn auto-attack off and also the auto-cast for Repair Bots. The first ensures the Demo Bots get spread around, the second prevents the Hoshiko from draining anti-matter too quickly. It's a good idea to have at least 20 Hoshikos for fleet repairs after a battle. If your enemy has a lot of cruisers and frigates, build even more Hoshikos for the Demo Bots. The AI will always have ships for you to shut down, but human players allegedly often stop building frigates/cruisers in the Rebellion late game. If your enemy doesn't have frigates/cruisers, scale back your Hoshikos.
Percheron Light Carriers are essential for countering bomber spam. Even the AI likes to rely on large swarms of strikecraft in the late game. Gardas and Shrikens counter bombers, but given how dangerous large groups of bombers are, you need to take them out of action as quickly as possible. 20+ Percherons loaded with Fighters will go a long ways to helping your other anti-strikecraft methods to keep the 'skies' clear. After the enemy fleet is destroyed, the Percherons can scrap their Fighters and build Bombers (if they have anti-matter left) to help destroy fixed defences. I say 20+ carriers, emphasis should be on the plus if the enemy is massing bombers. Fighters counter bombers, but not as quickly as you may assume, so you need a LOT if the enemy has gone bomber crazy. At least a 1:1 ratio (in addition to your other counters).
Garda Flak Frigates are my personal favourite frigate. They're fairly tough to kill, even before the hull and armor research, and they keep the fleet safe from strikecraft and corvettes. If they are placed in the middle of the enemy fleet they do respectable damage to long range frigates and support cruisers as well. Working within the radius of an Akkan's Targeting Uplink greatly enhances their lethality to strikecraft and corvettes, as do the autogun weapon upgrades. I'll have anywhere from 40-100 of these in a late game fleet. Note, however, they are still frigates and suffer in the face of late game Titan area of effect abilities. All frigates should be held back from battles against Titans until Disruption Matrix and EMP Charge can create a 'safe' environment.
Ogrov Torpedo Cruisers are essential for taking down enemy starbases and other defensive structures. Don't go on the offensive without at least 15 of these. 20 is better. 50 can tear even an Orkulus apart very quickly, but puts a heavy burden on your fleet supply. Fortunately, the Kols + Marzas + Dunovs + Ankylon combo can also dish out a lot of pain very quickly, so a smaller number of Ogrovs is acceptable to use in support. 15-20.
Shriken Corvettes are one of the key components of a TEC Loyalist fleet, as far as I'm concerned. Because of their fragility it can be a good idea to keep them out of a battle until the midpoint. Other times you may need their anti-bomber capabilities ASAP. They will target Bombers while targeting other ships and can do a good job of thinning out bomber spam. The Shriken really shines at the end of a battle as the enemy tries to retreat. Every attack the Shriken makes has a chance of inflicting the target with a movement, acceleration, and turn rate penalty of -25%. The effect can stack, slowing all movement to an absolute crawl. This basically means that an enemy can't retreat from a lost battle against the TEC Loyalists. All corvettes do bonus damage to Titans, as well. To be effective in the late game, Shrikens need to be used in large numbers. 50-100 are good. Some situations (such as the enemy having a high level Titan) may call for even more Shrikens to counter. Note: Vasari Titan AoEs can, unusually, affect corvettes, adjust accordingly.
Some ships are situational and should be built to counter enemy fleet composition, they may or may not need to be present in your fleet at any given time:
Cobalt Light Frigates can be useful when the enemy has a lot of support cruisers. Sabotage Reactor will damage the cruisers when they use their abilities and disable said abilities for a brief time. It's not overwhelmingly great, but it helps and the Cobalt does extra damage to support cruisers. However, even with hull and armor upgrades the Cobalt is not known for durability or for damage output against targets it's not meant to counter. If the enemy has a lot of support cruisers or flak, build Cobalts, but build a LOT of them to be effective. 50-100. If the enemy isn't building a lot of support cruisers or flak, Cobalts are probably not worth having in your fleet.
Javelis LRM Frigates remain the best focused DPS/cost frigate/cruiser in the game. However, they are hard-countered by corvettes, fighters, and heavy cruisers (meaning these units do a lot of bonus damage against the Javelis) and soft-countered by flak and bombers. As the most fragile of the primary TEC combat ships, these are also the most affected by area of effect attacks. Once upon a time, these were kings of Sins, but now they have two counters that become available early in the game, and one of those counters the other, so that most players will be building one or the other en masse at the beginning of the game (flak or corvettes). Late in the game, however, when the Javelis can be had in large numbers (50+) as part of a large fleet and after Clustered Warheads has been researched, they can be very effective against any target. They will take losses, but the TEC Loyalist economy can afford to replace them and with the hull and armor upgrades they will almost certainly dish out more damage than they take before they die. The only reason I don't have them in the essential list is because a capital heavy fleet already possesses a lot of high DPS output from the Kol/Marza contingent and may benefit from more Percheron Light Carriers and/or Garda Flak Frigates than Javelis LRM Frigates in some situations.
Kodiak Heavy Cruisers. Honestly, I don't use these ships. I'm constantly wondering if I should, but I see them as a high damage, high durability midpoint between the combat frigates and the capital ships, designed to give muscle to the fleet, but they have short range and no useful special ability (Intercept was useful in earlier versions of Sins, but the Shriken now does a better job of chasing things down and killing them, in my opinion). When 1/3-1/2 of fleet supply is being used on capital ships, particularly Kols and Marzas, the niche of high damage, high durability ship is already filled and frigates/cruisers should be chosen primarily for their abilities (which is backwards from the norm, where one chooses capitals for their abilities and frigates/cruisers for DPS output...). The Kodiak is not a bad ship, but there's limited Fleet Supply to work with, and tend to use it up on other things. I'm reconsidering this approach, but haven't come to a conclusion. For what it's worth, they are the best ship counter to long range frigates and they tear up support cruisers. On the other hand, fighters do even more bonus damage to long range frigates and you should have plenty of those and the Kodiak doesn't have a disable ability to use on support cruisers like the Cobalt.
Fifth, if all of the above section didn't make clear: fleet composition (of frigates/cruisers) should be chosen to counter the enemy's fleet. There is no 'right' mix of ships that holds true in all circumstances. Don't waste time trying to figure out the 'ideal' fleet. Even the exact composition of the capital ship component should take circumstances into consideration. The TEC Loyalist economy and the rate they can construct new ships means that not only can they replace losses quickly, they can also scrap and re-tool their fleet if need be. It's drastic, but if your scouting shows that you've made the wrong choices for fleet composition to counter your foe, it may be necessary. Try to do better scouting earlier to avoid this eventuality, however.
Sixth, using static defences intelligently separates a skilled defensive player from someone who has fallen into bad habits against the AI (it's really easy to do). Static defences should supplement the firepower and durability of your fleet, not act in lieu of it. In the worst case, they should delay the enemy for your fleet to arrive. I could write as much as I've already written about the general theory of static defence and how it applies to Sins, but not just now. I will say that Gauss Defense Platforms, Repair Platforms, and Hanger Defenses are all excellent in their own way, but for TEC Loyalists the Twin Fortresses are the real shining stars. Unlike the AI, though, it takes thought to force a human player to deal with static defences instead of circumventing them. Flanking a Phase Jump Inhibitor with Argonev Starbases and surrounded the whole in a knot of Repair Platforms and Hanger Defenses (and a few Gauss Turrets) is one possibility, especially if Auxiliary Government is upgraded on one of the starbases. Ultimately, though, it takes a fleet to fight a fleet: don't over-estimate the impregnability of defences, even while learning how to get most use out of them.
Once again, I didn't get to everything I wanted to, but I'm too tired to keep writing and editing. It'll have to wait. Remember that no matter how stridently I present my case, the proof is in testing. I make no claims to infallibility* and encourage testing and feedback. Theory only goes so far! Even compelling, sexy, iconoclast theory, sadly.
*To prove the point, I spent a year trying to theorize an effective counter to the dreaded Pikemen/Trebuchet combo in the Middle Ages and Renaissance Eras of Empire Earth, after trying many things I was forced to stubbornly concede that there wasn't a counter. It was a serious flaw in the game - and a colossal waste of time.