Blocking, blocking, blocking. Reece is a great running FB but he is not a huge impact in pass protection. Kuhn is a short-yardage back, who is excellent in pass protection (i.e. what Full Backs are called on to do in today's league, if they are called upon at all).
Blocking isn't as important for TEs any more but it is still crucial for FBs (because most teams would rather give the ball to a RB than the slower FB - I know Reece isn't slow, but he is slower than your RBs).
He did Aaron Rodgers is rated at 98 overall, if you are referring to Brady being a 93, take a look at his last 3 seasons, last year was especially down but he hasn't been the dominant QB he has been in the past. I think he's a better QB than Wilson, so I find it odd that he is sitting at a 93 with him (pulled the same overrating crap when Eli Manning won the SB too, though I think Wilson is a more solid/consistent QB than Eli).