After looking at some highlight film, I just do not see Johnson playing low post in the B1G.    The Clips I saw - which I assume show him at his best - make him look like a slasher type who can step out and hit a mid-range jumper.  
He looks athletic enough to contribute in the B1G.   Jumps well, blocks shots.   but definitely a forward.  
So, the low post situation is all about whether Robbins gets the waiver.  Without Robbins, you're looking at Curry and Freeman in the post, which would leave me very nervous.   
And - it's on another thread - Willis is leaving as a grad transfer!   
The Roster churn continues.