Game only fun early game!

Unlike Sins 1 Sins 2 is only fun early game pve which is all I play co op with a friend. The game is great early game but as soon as we get fleets up every single game we have ever played of Sins 2 the AI just jumps on a sword and dies. Have we lost games in  Sins 2 yes but it is always early game loses never the mammoth battles like in Sins 1. We play a lot of random map games with ai at unfair and they are always blow outs with the usual tough in the early game and AI falls flat on its face late game. To me once you get a good sized fleet up just restart the game you will just roll over the AI every single time no matter what hardness setting you use since the hardness setting seems to do nothing.