Per Adam Schefter, Michigan has its Jedd Fisch replacement, and it's a doozy:
Former Browns Asst HC Pep Hamilton had accepted an offer to become Michigan's Asst HC/passing coordinator, per school source.
— Adam Schefter (@AdamSchefter) January 9, 2017
Like Fisch, Hamilton has been a college and NFL offensive coordinator. Unlike Fisch, he is leaving his current job of his own volition, probably because it's the Browns.
In 2011 and 2012 he was David Shaw's offensive coordinator at Stanford; the Cardinal finished 8th and 29th in S&P+. (That second year was post-Luck, FWIW.) After 2012 he followed Luck to Indianapolis, where he was the OC for three years. The Colts finished 13th, 17th, and then imploded thanks to a spate of Andrew Luck injuries and poor play when he was available. Hamilton was fired midseason in what was widely regarded as a Jed York-esque scapegoating. Hamilton was well-regarded around the league just a few months before he got the axe.
That's a pretty good resume for a coordinator; Hamilton is coming in as a co-co-coordinator. Meanwhile any QB coaching issues that may be inferred from Luck's terrible no-good 2015 should be obviated by his head coach. Also he might make a good head coach candidate when Harbaugh leaves for the Rams. (Did the Rams already hire a coach? Does it matter?)