So a video showed that a 5'8" could dunk and looked like he may have been somewhat quick. From that you're asking whether or not he could have played in the NBA? My guess would be no because the NBA is the most difficult league for athletes to break into because teams carry only 15 players and there are only 30 teams. I've played with more than one 5'8" who was quick and could dunk. None of them could have played in the NBA. How many brothers have played in the NBA? Not that many in relation to how many players have brothers. So i would bet that if this dude was MJs height that he would not have played in the league.