No. Arthas chooses to follow orders like the Cult of the Damned. The Scourge have no choice, they are locked inside while their bodies act without their will.
Yes, that can happen in other stories. But that's not what happened with Arthas. We were given the info from his PoV, the voice of reason and humanity was separate as was the voice of Ner'zhul. From Arthas' own PoV, he acted of his own volition and enjoyed doing the LK's bidding. In contrast when we see Sylvanas, her body is bound to the will of the LK despite all her anger and hatred. Sylvanas was just a passenger.