I'll state this again, we are best when we play man, it's a different skill set playing off and zone, when you are a press corner you get your hands on a receiver and redirect, that's a strength of Simon and Sherman, Sherman is so long he also can play the zone, Guys like Lane and Burley are quicker and play the slot better.
When Simon is asked to play zone exclusively he is not at his best, seems to bite on moves and recovers slow.
Quinn played more man in his defense, Bradley and now Richard play a lot more soft zone, it's asking guys to use a different skill set, some have that ability and some don't, a guy that is a zone defender has a harder time going press corner, might be size and strength but it's a skill fit, same the other directing with reading a receiver and film to know how they come off the line when not being jammed and what kind of moves they use a lot to be able to stay close in coverage.