The Lenovo Y580 has a very good cooling system...whether it is better than the Asus G75VW I cannot say since I have never seen a G75VW....however, I doubt the Asus G75VW could be drastically better...
I've played Shogun 2 total war at highest settings and 1080p, no problems and no real heat issues...Civ V also works just fine...it's not the best out there but it is very hard to beat for its price as a laptop...
I bring up the Lenovo Y580 because it is almost as good as the Asus G75VW but will likely be cheaper...since you aren't in the US I have no idea what prices you can get, all I know is that from where I am the Lenovo is cheaper by a decent margin...ultimately you will have to decide whether the Asus G75VW is worth the extra cost...if it's $100 more, it'd be worth getting...if it's $500 more, I'd probably go with the Lenovo instead...
Other things to consider: what is the available warranty for each laptop? Does the Asus have options for a solid state hard drive? I know the Y580 can come with a small solid state for your operating system (makes your system run really fast) and a normal hardrive for everything else...
If you do get the Lenovo, make sure to get one with 1080p screen...the default is not nearly as good....