Harbaugh is ranked #23 overall, which puts him just outside the top third of Power5 head coaches, which isn't too bad, I guess.
But Harbaugh is seventh among Big Ten coaches behind Indiana's Tom Allen (#20); Wisconsin's Paul Chryst (#18); Iowa's Kirk Ferentz (#17); Penn State's James Franklin (#13); Northwestern's Pat Fitzgerald (#8); and of course our very own Ryan Day (#4).
As far as Michigan being a solid top-20 program, here are their AP Poll finishes over the six years of Harbaugh's tenure:
2015: #12
2016: #10
2017: N/R
2018: #14
2019: #18
2020: N/R
Not too solid, IMHO, and a noticeable downward trend, but for some reason CFB writers can't get over their love affair with Harbaugh.
Bottom line is this: Harbaugh, unlike every other coach in the Big Ten with the possible exception of James Franklin, was specifically hired to beat Ohio State. Coaches don't get hired anywhere else to beat Ohio State because history shows that that's simply not a sustainable plan for success - Ohio State's record against the rest of the Big Ten besides Michigan is 488-137-22, for a .771 winning percentage. Harbaugh had one job, and to date he hasn't done it.