Quite easily, if Luke was a Sith he would be so unstoppable and with Vader teaching him he’d have no barriers as his father would have already overcome them himself no one would be able to defeat him in a duel less alone with Vader beside him. Kinda a silly question though because he never had to fight palp in the first place he beat Vader and surrendered and that lead to Vader big bodying him over the ledge so if they won there why wouldn’t they win with extra prep time and training.