Double won a tournament in Tekken 8, but Malgu has never won a tournament. IMO they are about the same level, but Double plays more defensive which is harder to win in Tekken 8. Tekken 8 doesn't favor defensive playstyle, but Double's law made it because every aggressive laws failed in tournaments.
Double's pressure game is God like. Once he downloads his oppenents playstyle, his Law becomes a Rubber Wall that is closing in. He uses every tool that Law has to bait and punish his opponent optimally.