Top 5 defenses not a surprise, IMHO. I think Perich will have a fine year at Oregon. Won't be any confusion of roles (or prima donna status); he'll be deployed to play to his strengths in a defense that brings huge pressure on the QB. I bet he will have 6 interceptions, at least.
I think it gets much more subjective--or hard to predict because of roster turnover and coaching changes--from rankings 6 on down. In the Gophers' case, I believe they played below their defensive potential in 2025 due in part to Collins' learning on the job (including the failure to mentally prepare depth players pressed into service by injuries). The NW game, deep into the season, was a planning and preparation debacle on defense--wasting a great offensive performance. I think that Collins didn't play college football (might not have played HS football). I suspect that, in his first year as a DC, he might have under-appreciated how hectic and confusing it can be on the field for defensive players when offenses attempt to confuse defenses through last second shifts, motion, counters, etc. The best way for an offense to overcome an athletic defense is to cause decision-making confusion on defense = explosive plays. Conversely, defensive athleticism flourishes when decision-making is kept simple and crisp. It feels like we replayed the Robb Smith movie on defense at times last season.
I think the Gophers' 2026 defense, even without Perich, has as much talent or even more than the 2025 version (because of maturation across the board). If Collins gets better at opponent-specific game planning and in-game adjustments, and perhaps diminishes the decision-making complexity that can cause a defense to lose a step (or focus) at the snap, he has the athletic talent and experience on board to snuggle up to the at least the 6th position in the B1G, maybe higher.
Go Gophers!