Morale is not one number.
“Morale is the commitment the combatants have to their leadership and their cause. To simplify a bit, we might say that soldiers with good morale believe three things: that their cause is a worthy one, that they are on the road to success and that their leaders have a good (enough) plan to achieve final victory. Poor morale can result from a breakdown in any of those three elements: troops might for instance believe both in their goal and its eventual possibility but not in their leaders to produce it (this seems to have been the case, for instance, in the French Mutiny of 1917, discussed below). On the other hand, regardless of the charisma of leaders, few people come to a war intending to die in it; if the cause appears impossible, morale will sink regardless. And armies that do not believe i”