Layne Vashro, who has some respect among analytical types as a draft-pick modeler has his as-of-now forecasts up and available
here.
I'm not endorsing or criticizing his modeling. I just thought it might add a bit to the conversation. In my checking of previous years' results, he's had successes and failures, but there seems to be enough there to at least make it a point of consideration.
There's more to his forecasts that you can look at yourself, but one of the things he does is give odds of players reaching various levels in their top NBA season: bust, bench, starter, stud, star (based on win shares). If he turns out to be accurate, it's good we're in the Western Conference. The likelihood of getting a decent contributor drops off a cliff after #13. Here's his odds:
Okafor -- bust 2%, bench 9%, starter 26%, stud 23%, star 40%
Russell -- bust 1%, bench 1%, starter 24%, stud 33%, star 42%
Mudiay -- bust 0%, bench 1%, starter 27%, stud 34%, star 38%
Towns -- bust 1%, bench 6%, starter 31%, stud 34%, star 28%
Johnson -- bust 3%, bench 11%, starter 40%, stud 20%, star 27%
Hezonja -- bust 8%, bench 4%, starter 63%, stud 12%, star 13%
Porzingis -- bust 73%, bench 5%, starter 19%, stud 2%, star 0%
WCS -- bust 3%, bench 9%, starter 29%, stud 46%, star 13%
Oubre -- bust 1%, bench 12%, starter 56%, stud 18%, star 13%
Turner -- bust 20%, bench 18%, starter 38%, stud 15%, star 10%
Looney -- bust 13%, bench 23%, starter 44%, stud 17%, star 3%
Winslow -- bust 35%, bench 18%, starter 35%, stud 8%, star 4%
Kaminsky -- bust 23%, bench 30%, starter 33%, stud 12%, star 2%
Only one other player (Christian Wood) is rated more than a 26% chance to be better than a bust or a bench player in their best year. Here's the probability he has for bust/bench outcomes respectively for some of the players that may be of interest here:
Booker -- 90/4
LeVert -- 65/16
Harrell -- 67/23
Portis -- 65/23
J. Anderson -- 75/12
Grant -- 72/19
Lyles -- 77/15
D. Wright -- 50/25
Dunn -- 49/37