Well, I'm through with the game

[Twan]

Should I be setting them to Offensive? I just have em set to Random behavior...

I think the sooner AIs attack the best it is for them, as they are mostly bad in the magic area (playing with very difficult research should help them too).

Offensive AIs attack more both other AIs and players.
But if you set ten AIs on offensive on a small map, I think there are good chances that some of them gang against you (especially if you have a better start than most AIs and so have several neighbours fast).

There is also a map command to avoid to see AIs fighting each other (but it may lead to some AIs not succeeding to expand as another AI hold a crucial chokepoint).