Yes but not for a long time. Tyson in this day and age could walk right through john ruiz in the first round with not much effort, but if he went in there with a good opponent such as a Vitali Klitschko or someone who would be able to handle his punching power, then it would be a different story.
Floyd would destroy leonard to an easy UD. sugar always tried running away from his opponents and tried winning by using his speed. Floyd is extremely quick and wouldnt have a problem outworking SRL imo
Brock looks to be the most promising of the heavyweight contenders, he has a good amateur background, good skills, heart, and still has a 0 on his record.