Brock really is the only guy who has come over and done well in the UFC. He became the champion and a lot of people attribute this to his athleticism and that he was a great amateur wrestler.
Who else would be able to come to the UFC and maybe win a few fights with some training?
I personally think guys with wrestling/athletic backgrounds would have fared well in the UFC.
Kurt Angle (in his prime, Gold medalist and also known for being a tough guy)
Jack Swagger (Div 1 wrestler, guys a freak athlete)
Dolph Zigler (dudes a div 1 wrestler/ freak athlete)
Triple H (also a freak athlete, charisma,known tough guy) (I mean in his prime obviously)