While I agree that Kun is more powerful than either Zabrak, I question whether either Kun or Uliq is a more skilled duelist than Maul, who is regularly and consistently touted as one of the most skilled warriors in Sith history and a high end master of multiple forms, or at least to the extent to challenge Sidious.
Without the Force, Q is right, this is a much harder contest given that Kun is considerably more powerful (if not more skilled) than the Jedi Sidious blitzed and faced.