Battleground editor usefulness?

[NTJedi]

Endoperez said:
Having a modding command that makes a province to use a spesific battleground would be interesting.

A modding command or a mapedit command would be nice. I'm not sure how armies would react if obstacles were placed within the center of the map. Are they smart enough to walk around the obstacle or would the attacker and defender to be stuck on each side until forced to retreat? I ask since I don't see any current battlefiled which has obstacles in the middle of a map.
I estimate it wouldn't be an issue since castle walls don't cause blocking issues.