Now, question is, were they Turks or were they Christians from throughout the other parts of the Balkans?
First time Vlad did that, I would imagine the second time the Turkish field commanders gave him nothing but Orthodox cannon-fodder.
If I remember my reading history correctly, Vlad impaled anyone and everyone that collaborated with the Turks. Dude, didn’t play around and he’s a hero IMO. He slowed down the Turks significantly from continued movement into Western Europe.