That's what "complementary football" is supposed to look like (you need a stout O-line and a run game to succeed with it, not to mention a top tier D).
Speaking of UM's D, it was not only dominant, but pretty unique in college football.
Harbaugh got a huge assist from his brother in that his past 2 DCs were promising, young assistants from the Ravens (the DC that beat CJ Stroud is now the DC of the best D in the NFL).
So, UM's scheme is basically a Ravens-lite scheme build to defend against Day's dOSU offense, which coincidentally, was well suited to stopping UDub's O with Penix.
Not surprisingly that Penix didn't have his best game with all the pressure he was facing and the different looks the secondary was throwing at him.
Harbaugh is probably leaving for the NFL and will be taking his DC, Minter, with him.
All the recent success wouldn't have happened if Harbaugh hadn't moved on from his long-time DC, Brown.
When Harbaugh asked his brother for help in beating dOSU, John offered Jim a choice of 2 defensive assistants.
Jim picked MacDonald and the other assistant, Minter, went to Vandy as its DC, but when MacDonald moved back to the Ravens, Minter took the spot.
Despite the lack of 5* recruits like Bama, UGA, DOSU - UM, this season, made up for that with a lot of 4th and 5th year seniors.
And on top of that, put their players in a position to succeed with great schemes on both sides of the ball (the use of motion, switches, stunts, etc to keep the opponents guessing).
Fitz had the right idea with going with an NFL passing D scheme, but picked the wrong scheme/guy.
Instead of the read/react crap we've seen fail time and time again, UM went with a scheme that causes the opposing D to try to react to what they are doing (that is, if they can decipher the different looks the D is showing).