Ross there is no shortage of MMA fighters with reasonable boxing experience.

Yosuke Nishijima - Wikipedia, the free encyclopedia

This guy as you can see actually held some smaller cruiserweight belts and a decent record...5 MMA fights....5 Losses, 1 K1 fight.....1 K1 loss
Boxing is a part of MMA but great boxing does not equate to beating 99% of MMA fighters.