As far as I know, Chuck Norris didn't compete at full-contact karate nor in kick boxing. Only at point-karate. But Bill Wallace, Benny Urquidez and Joe Lewis did ( Don't confuse him with the boxer named Joe Louis. They are different persons )
Do you think Benny would have beaten all the 3 guys at full-contact karate or kick boxing?
I know there was a considerable weight difference among them:
Benny Urquidez was lightweight
Both Bill Wallace and Chuck Norris were middleweight
Joe Lewis was heavyweight