I second the comment about the AI being far too timid in campaign mode, especially in custom campaigns.
I'll play the AI on one of the custom maps, where most of the territories are neutral to start. I expand quickly, whereas the AI only proceeds one territory at a time. By the time we meet, I have 3/4 of the map. Also, the AI spends a lot of time ferrying units back and forth between territories for no apparent reason.
I would like the option to play against 2 or 3 allied AI opponents