Id ask whether youd rather die or be a slave. You can ask almost any man that. Theyll die. Almost any free man will take torture and death over slavery. So we can assume slavery to be ethically worse than genocide. We can see today that genocide is actually practiced while not under world scrutiny, china is commiting genocide in both #freetibet and the Uihgur Muslim population. And the world is not in uproar. Now say china said "slaves for sale, muslims." We would wipe those fucks off the map.
Hence logically slavery is considered worse than genocide. So the Confederate democrats are worse than the german Nazis.
this would fry an npc's brain quite efficiently.