Another issue that i don’t like is retreating mechanic. It should be more realistic, your mercenaries should retreat only when they are next to end of map and only if there are no enemy close to them. Retreating should be treated for any battle brother separately. In this case you should sacrifice few of your battle brothers to give opportunity to run away for other brothers. It is more heroic and realistic than now.
That’s the way it works already. Move your guys to the edge of the map and hit retreat – everyone on the edge will safely do so. Anyone not on the edge of the map has a high chance of not making it out alive.