I've filled a gap in my "Tricorne Wars" rules. Previously, other than morale penalties, I had no mechanism to cover the situation when units suffered massive casualties. So I've now added the following:
"When units are reduced in size beyond a certain point they can no longer rally to improve their Cohesion. These size limits are:
Hopefully this will serve to alleviate the situation where only one or two figures were left in a unit.