True, but that's a lot more realistic. A small skirmish that you win would yield a little morale boost for the victory and only a slight drop due to fatigue. A battle that spans numerous skirmishes would net you a lot of immediate morale gains from victories, but take a heavy toll on your group due to fatigue. The battle weariness effect improves a lot faster than the boosts from winning is reduced. Where weariness will kick your party's morale in the teeth is if you continue to fight battle after battle in a very short span without rest.