Sam Hubbard had no experience at DE (and inferior physical gifts to Gary's) and after bouncing from LB to TE to DE at Ohio State, and then 3 years with LJ, became a starting DE in his 1st year in the NFL.
Hubbard was not a borderline 3/4-star. He was ranked 102 spots higher than Winovich as a recruit. Although both had similar backgrounds in moving around positions and both had similar sack numbers, Winovich far outpaced his tackles numbers and was a 2-time first team all B1G performer and second team All American..
What it was at Michigan that didn't allow Gary to get developed I don't know - overall culture, strength and conditioning program, position coach, what he was asked to do in the defensive scheme.
If that were the case you'd expect to see an uptick in Gary's numbers in the NFL with better coaching and a better program, but that didn't happen.
Although there are exceptions, there DOES seem to be a problem generally with player development at Michigan. That's not MY read as a Buckeye fan; that's the read of lots if Michigan fans at Mgoblog. A HC who is paid as much as Harbaugh should be able to fix it. That he hasn't is ok by me.
That's another question about a different coach with a different set of criteria.