Death will never be wasted, when a warrior falls, their soul will be passed into the Realm of Souls, where it will benefit and heal those still fighting, and ultimately summoning ferocious Ushabti to the field of battle, an elite monstrous infantry.
The legions of the dead are vast, but they are also frail, Skeleton Warriors and spearmen are best suited to holding back the mortals, not cutting them down, so don’t rely on them to do any heavy lifting.