I say change it for the base maps, but if you have high enough pathfinding/tactics, you can "choose your terrain" sort of. Basically if you have a certain amount of points in the skill, whichever one, you can choose to fight in a rolling hill area, an area with a river, a canyon-y area, an actually mountainous area instead of the crazy mountains, or, if you really want to, the crazymountain area.