Johnson hasn't fought anyone worth noting yet . He could turn out to be another Houston Alexander. Rich Clementi choked him out. Josh has fought some of the very best in the World and has beaten some of them. Josh's wrestling ability is as good as anyone at Welterweight. Josh has only been Ko'd once. Lets see how Johnson looks when he gets taken down and it will happen.
Kos is one of my favorite fighters but I wouldn't put it past him to try to stand with AJ and get KOd. Unfortunately it isn't uncommon for a good wrestler to have some good striking fights (usually against other wrestlers or JJ fighters) and then they suddenly think they can strike with quality striking fighters.