Victory would be gained. The rivals that had blacks on their army would mean two hands instead of one. (They have more men fighting alongside them.) The Northern armies that had liberated the slaves did not know what to do with them. At first they just put them, to work performing lowly fatigues, presently giving them uniforms as the only clothing available.Then some of the junior white troops saw that it would help their promotion if blacks were recruited into the rifle-ranks.Eventually whole black units were raised.