I absolutely disagree with any system that has Purdue in tier 1, regardless of what KenPom says. The defense is a tier 1 defense, the offense is tier 3 or 4 at this point. If the offense gets fixed, this might be a tier 1 team. But it's nowhere near there today, and we don't see evidence that it's turning around.
I don't think you move Nebraska up. They just lost at home to KenPom #232 North Dakota. Their two B1G games looked like they were maybe turning a corner, but that suggests not, and that their home court advantage isn't sufficient to be projected to beat any of those teams in tier 3.
I think Hoiberg might be a good coach, and he might have enough talent to upset some teams [as done with Purdue], but tier 4 would project them to beat a number of teams that I don't think they should be projected to beat.