One more late post: There is a niche for an assistant that helps a player improve their play; I don't think it is filled yet.
Currently, the leadership assistant focuses on the basics of running the interface and on saying what your options are. Meanwhile, the advisors give some help with tactics, but they also advocate for their particular area, so it is hard to know when to trust them.
It would be great if there were an assistant that acted like a coach, and tried to help you "improve your game". It could look at a planet and suggest what you should have built a few turns back, or point out how you screwed up adjacency. Or it could look at a battle, and point out how a few ships of another kind would have done a lot better. In my experience, the best time to learn is right after I've screwed up. That would be the time for the coach to appear and give me a better way of understanding what happened.
This kind of assistant would take some more effort to build, because it would be very contextual. One answer would be to allow the community to build them, by giving the mod interface access to the necessary information. A new player could then add a set of community built expert coaches to look over their shoulder.