To answer my own question, I think my top 12 RBs look like this:
T1 - Barkley
T2 - Kamara, McCaffrey
T3 - Zeke
T4 - Mixon
T5 - Chubb, Gordon
T6 - DJohnson, Bell, Gurley, KJohnson, Jacobs
Zeke scares me a bit. He needs to lose some weight and cut back on the partying. While he has good hands, if the offense improves, his targets will dip. Great talent, but I feel better about Kamara and McCaffrey right now.
I hate Patricia for Kerryon, and there are injury concerns, but he’s young and looked great to me; I’m sold on his talent.
Jacobs’ ranking is a bet on his draft capital, opportunity, youth, and receiving chops. I’m not 100% sold, but everyone in the tier has question.
Guys like Fournette and Cook, while talented, are too risky to value top 12, IMO. They would be in the next tier.