I think you're ignoring or underplaying the fact he's a strong man playing against a lot of younger guys and he takes full advantage of it. It's also a very well coached defensive team surrounding him. And while he averaged 6.6 assists, that was only as a senior. His previous best was 3.7 his Junior season.
As for the Brogdon comparison, it's probably fairly accurate if you allow for the height and wingspan difference. But that's a significant difference and IMO it's the primary reason Brogdon is as capable as he is. And as capable as he is, the Bucks still went in search of a better starter at his position.
If he's there at 31, it wouldn't excite me but maybe it's worthwhile? But at 16, that's a real stretch IMO. He isn't going to drive and score all that often and he's going to be a fairly easy cover on the perimeter given his lack of quickness and mediocre shot. I just don't see him as a starter and unless we've solved that problem, I'd rather use the pick to get an actual starting PG.
And yes, Carter was the defensive player of the year (twice actually). But, IMO, in college that is a function of team far more often than not. Emeka Okafor won it twice too, as did Sheldon Williams and Hasheem Thabeet. A lot of players that failed to make a mark in the NBA won it also. Players such as Jim Mcllvaine, the same stiff that drove Shawn Kemp to his silly holdout.
A few of the NBA comps on him are Lindsey Hunter and Derek Fisher. I think they are reasonable comps but both players benefitted from playing in a league that still allowed forceful hand checks. If Fisher couldn't use his hands and body to re-direct the ball-handler, he'd have been out of the league more than a decade earlier.
I just don't see anything special with Jevon when you remove the advantages he has as an adult amongst boys. His lack of a first step, his poor ball-handling skills, his subpar finishing at the rim, questionable shot selection and unexciting measurements makes him a second round pick who will aspire to role player mediocrity if he makes the league at all. JMO.