More well rounded or not, Mayhem still submitted Sakuraba, something no-one had done to him since Kimo in '96. He really isn't. He's fought Mayhem, but his striking isn't as dynamic as Mayhem's and he's not as aggressive on the ground as Mayhem. Sure, he will help Diaz, but he's not going to improve Diaz's wrestling enough to help him defend Mayhem's takedowns. Mayhem is 6 ft 1. Nick Diaz is 6 ft 1.