Actual battle wasn't that deadly during this period, apart from some instances which are rather the exceptions proving the rule. Most losses happened when one side ceased hostilities and retreated/routed (depending on how orderly, etc). Could this be a viable game mechanic? In peace deals you could recoup part of the manpower that way? Of course there would have to be a system created that in battle would calculate deaths and wounded/captives (depending on what for a rout the retreat was the wounded were generally captives of the victor). I could even think it through a bit more and have entire hosts of mercenaries switch sides to the victor, also not uncommon.
