I notice the AI for the different demigods either is good or sucks. Some of them do not really help the fight at all, but run back and forth between the base and the battle lines, doing a little or capping flags (which is ok, but can really cost you late in the game when you need fighters for the push).
In a long running game, a rook AI literally has become a lane controller where you cannot take him down due to his ability to heal and huge health. Not 1v1, but rather he is swarmed by giants and lower and you're hitting him in the butt while he ignores you.
That would not be so problematic, for example, but because either your "teammates" (AI) is having a pow-wow in the middle of the map somewhere playing craps for stolen gold or you got lucky and its pwning the game for you.
The general types in particular are problematic, though Erebus seems just fine. The Oak and Queen lack any punch (including all their assets, i.e. minions) and Sedna does little damage, but can stay alive forever (which is ok, I guess).
A few tweaks are necessary I think. It sucks being saddled with idiot AI and the enemy luckily getting the demigods that have effective AI (or are more effective with the all purpose AI, I don't know). It also sucks to go finish making dinner while the game runs long and come back and find out you won in a 1 Player 2 CPU VS 1 Player 2 CPU match. You weren't even needed.