I'm currently in a "pitched" battle against the AI (See the image below).
http://img703.imageshack.us/img703/2772/xqjr.jpg
I refuse to move my troops forward because there is no way I am I willing to pass up on the possible swarm bonus but the AI, recognizing that fact, also refuses to move up.
That would be fine and dandy if I didn't have archers. I can happily pick off each enemy at range and the AI refuses to move up. Maybe add in a check for this sort of circumstance? There is no way the AI can win if it does nothing; even if it's the "best" move.