I think if anyone had been in command it would have been different. Piett was obeying orders from Palpy, but Palpy wasn't paying as much attention on the battle as he was putting on Luke, the same goes for Vader. The Grand Admiral apparently didn't have a great effect on the battle, one of them was more concerned about Palpy than about the Rebel fleet (the force-sensitive one). Piett didn't know what to do, and with both the Executor and the Death Star gone who would they listen to? Pellaeon? He wasn't even captain at the time... The Grand Admiral that was more worried about himself than about leading the Imperial forces? Sure, Thrawn might have come up with a smart tactic move to counter the Ackbar Slash, I doubt that Palpy would have brought him to Endor.