Minnesota was ranked #31st in defense last year (S&P) he had a passer rating of 179.12
Purdue was ranked #53rd and he had a passer rating of 81.96
Wisconsin was ranked #29 and his passer rating was 69.48
I think it’s fair to say he was inconsistent last year no matter what defense he was playing. Sure against the better defenses he was worse and against the worse defenses he was better but still inconsistent week to week.
By the way BYU’s Defense was ranked #49.
http://www.footballoutsiders.com/stats/ncaadef