It is not exactly like killing a human. You should still try to find other ways. Similar goblins are not exactly like humans. Which is a point you are missing here. You can't have it both ways. If they are exactly like humans raiding villages and taking slaves would probably warrant war. Especially if you are a poor farm village. What could they do? Do they jail them? That is alot of mouths to feed in a hard winter. The nobility is not going to help them now. They definitely aren't going to pay for goblin rehabilitation. These aren't modern people. They don't have modern resources.