As amazing as Schindler's actions were, they ultimately had little effect on the overall scene, such was the scale of it. He fought the monster and survived, not fought the monster and brought it low.
Schindler saved a thousand people through some pretty ballsy actions. But for scale, the battles of Stalingrad, Leningrad, and Moscow each had total casualty rates for both sides of 1-2 million people apiece.
See also Schindler's List for an example of how a contractor of the enemy can undermine it.