What I mean is - Warmaster is an abstract game where the units you have could literally represent just 30 high elf spearmen, or 300 or 3000. A couple of buildings that would barely be a hamlet actually represent a town etc.
So stone walls could lower movement for cavalry and infantry and force a blockage against chariots. But do work, mechanically in a battlefield? I ask as I've not noticed them in many battlereports.