I think steveson is too methodical for MMA. In wrestling he can stand around insulated by his athleticism (and earned skill), and out of nowhere pull out a seem-less set-up/shot/finish combination that blows your mind, and its really hard to crack his shell before he pounces...MMA might be too choatic for him.
I don't know MMA or anything, but I have a feeling a mediocre wrestler who lived his life in desperate choas might be better tuned for MMA than I freak who is used to controlling the mat almost every second of his career.