Pls explain Manny Diaz, who helmed the 7th ranked Big Ten D at Penn State last year, and has never statistically outperformed the Gopher D of the past couple seasons, even while showered in talent at Miami. The same is also true of Jim Knowles (Ohio State)
Jesse Minter (Michigan) has never been a FBS DC prior to last season. He got a near identical result in 2022 as Joe Rossi, with far more talent. He's a WR as a player but doing pretty well. #2 in America seems a stretch.
Also, are we sure that the best DCs also work at a short list of "blue blood" schools? Give me Parker, Rossi, and the other dudes making this list from medium-resource programs.