There are basically two ways of balancing a map. Either you micro manage the maps, like with counter-strike and similar games, or you go the more 'open world/sandbox approach' like battlefield. Both strive for balance, but one in the 'micro' and the other in a 'macro' way (I really wish we could have a more objective based combat). I believe that the scale of warband and cRPG is more suited for a more "open world approach" (read: sandbox) where balance is there, but maneuvering and positing is more important then rushing that particular spot on the map (which could be argued is the same thing, but the general scale and diversity of combat usually makes such 'spots' obsolete).
A cliche if you will: Less is more. Let the players dictate the flow of battle, not the map.
Lizard_man: I removed most of the Village maps, because I simply don't know which of them are good. I know there are a couple of gems in there, and I will start to poke them in again eventually. If you can remember the names of the good ones, please post em.