To be fair, most of Beilein’s teams only had 8-9 people worthy of playing.
Here’s how the rotations have played out with a cutoff of 12% of available minutes (>10% is what kenpom uses to define a non-rotation player but I’ll bump it up to 12%).
2008: 10
2009: 11
2010: 9
2011: 8
2012: 7
2013: 9
2014: 9
2015: 10 when healthy
2016: 10
Looking at the years with less than 10 it’s clear that Michigan didn’t have anyone else on the roster who was worthy of being in the rotation. I think if he has players who prove themselves to be good enough to play then they will get minutes.