I would like to respectfully disagree with the OP. I think that units should be able to be forced to give up and flee. I believe that it adds depth and strategy and realism to the game. Units willing to stand and die to the last man are extremely rare.
I believe it adds interesting tactical options when you have 'cascading morale loss'. This way you can turn defeat into victory by focusing on a small part of the (perhaps larger) enemy army to demoralize a key unit, then another, then another and eventually forcing them off the field. It would, IMHO, be particularly appropriate in a game with magic since summoned, undead or other magical creatures could be expected to be terrifying. Perhaps troops who have never encountered undead might be more prone to flee than those who had successfully faced them down in the past.
I suppose it could be an option to turn off, so the OP would be happy.
PS lwarmonger if you removed all but one of your repostings then people might respect your ideas more.