[Daynarr]

Forts are reported as fixed. I expect AI to be significantly stronger as a result.

There is this mod for Orania map (forgot it's exact name) that is basically map file for stock Orania map and gives 5 provinces 2 castles and some special sites to all nations in game. AI performs very, very well there.

If AI can build castles (and labs of course) then there is no reason to believe that AI will be weak.

Which reminds me, that Orania mod/map (called something like Orania hard, but not sure) is one of those mods Graeme is talking about. It's designed primarily for SP and to help AI while keeping things balance. Another mod/map was provided by no other then Gandalf Parker who has random maps generated with random alliances and random bonuses which make AI much more difficult and the game more unpredictable as a result.

Edit: Whoopsie, K.O. beat me to it.