I once defeated a superior force by setting up my spear units (fSgts&cSgts) between buildings and stacking my whole crew inside that perimeter. The enemy couldn't get a good flank, must not be programmed to destroy buildings to gain an access, and their vastly superior ranged units mainly were soaked up by some trees and buildings.

It was like one of those easy mountain defense maps where the no access zones allow you to make a wall of spears and pepper them with almost every volley from your crossbows. They just run around until there is a field of bodies to fertilize my mountain crops.