It's hard to know what really is going on inside Schembechler Hall and why things turn out the way they do. Michigan for example has some weird problem turning highly ranked RB's into college football stars. The lower ranked guys seems to perform better then the 5 stars, Michigan's new RB coach is a clear example and so is Haskins on the current roster (who was originally going to be a LB at Michigan).
This situation is why it isn't surprising that Zach Charbonnet is leaving Ann Arbor and in the transfer portal. Michigan fans fell in love with the talented RB last year has he ran for over 700 yards and scored 11 TD's as a freshman.