Hoke was 34-38 at Ball State, 13-12 at San Diego State and 31-20 at Michigan
Harbaugh took a horrible Stanford team and made them better every year until they turned into a powerhouse. What Hoke did at Ball State and SDST doesn't even compare to what Harbaugh did at Stanford.
Harbaugh's Stanford teams and players got better every single year in a major conference. Hoke's (teams and players) got worse every year in a major conference. I think it's pretty safe to say Harbuagh is better and will be better than either of the previous two Michigan coaches. You can see how the team is playing compared to last season to notice that it's all coaching.