He's about the least impressive of the big name guys out there doing it, in my opinion. And, yeah, you have to question the worth of rankings that change dramatically in some cases after just one year in the league. I know this stuff is just content that's manufactured for fun, but really, theres' a draft pick and there's the job the coaching staff does developing talent. You can't really separate those two easily after one season.
Plus, it's pretty obvious from his review that he didn't put nearly the work into watching the play on the field once the players get into the NFL that he (or others) did when the players were coming out of college. He's probably just looking at snap counts and going off of some recollections for however-few hours he ended up putting in on this.