White has fought in Pancrase, Pride, & the UFC. He has experience, and is knowledgeable. So, your basing his teaching abilities on his MMA record? Well, if we were doing that, then Pat Miletich is a bad teacher, because his biggest win is against Shonie Carter.
Renzo Gracie has an 11-6-1 record, does this make him a bad teacher?
Matt Serra is 5-4. I guess he's a bad coach as well.