Kevin Rosier vs. Maurice Smith.

Watching Kevin Rosier's old fights has really gotten me curious about the quality of fighters in kickboxing back in the day. Obviously there were guys who knew what they were doing (As evidenced by Smith), but Rosier was apparently pretty accomplished and he's basically Butterbean minus 100 or so pounds. Can I get some insight on this? My assumption is that Rosier had a lot of fights in the Superheavyweight division, where presumably many guys didn't take the game seriously enough to have strict dietary and training regimens.