I'm not interested in campaign balance or map changes though, just combat AI and behavior.
What's wrong with making the Campaign AI better? Seriously?
And it doesn't change the map at all. Darthmod is a pure AI mod.
If you really don't want this, can't help ya. This is the best AI mod that changes the very least to M2TW. All other good AI mods are packaged with other huge mods. :shrug:
http://www.twcenter.net/forums/forumdisplay.php?f=637 I could think of that changes nothing but the AI. I have no experience with that mod however, so I dunno.