The AoE cap makes this a issue anyway.
I don't like the morale damage concept at all tbh. These Morales should be dps boosts and debuffs in varius different ways. I belive it's possible to implement such a mechanic and still have it be as impactful as straight up unmitgble Morale damage without people feel like they couldn't do anything to prevent it from happening.
Unshakeble Focus was a good example of this. All it needed was a tweaking so it only affected AoE attacks rather then just being straight up removed.
The one good thing morale damage does is that it ballance any equity issues by ignoring most gear and renown difference.