Does he have the personnel to make that move right now will be a huge question. Think back when Rich Rod came in and wanted to run his system, the personnel just was not there and M fan were not going to give him the transition time to make it work. If Jimmy Football does not like the result, he will go back to what he knows and loves.
I don't think the personnel is the question. If anything, Harbaugh's 2018 offense was built for the wrong roster.
Patterson is a Tate Forcier/healthy-McSorely type. He was born to run to throw, run to run, and air it out. The top 3-4+ of the receiving corps are all future draft picks, likely including high picks. Whether they are among the most productive in college isn't about genes but the head coach's interests and the OC's tact.
Then there's Ed Warriner who did solid work in the power game in 2018, but became a commodity as an OL coach for his units on more spread offenses, and Michigan probably has one of the most nimble centers in the country. Many C's can't pull off one reach block ever. Like David Molk, Ruiz could reach all day.
So personnel isn't the real question, and this isn't like Carr-to-RR (in terms of fit, it's more as if Carr inherited the 2008 roster from RR or as if RR inherited the 2011 roster from Hoke).
The real questions are (1) is Gattis all that and (2) is Harbaugh as committed to his spread/RPO future as he seems? Tact and will. That decides this. The Johnnys and Joes are already in town.