Crowell for Carr or Prescott

Looking to trade Crowell who is just sitting to the David Johnson person for Derreck Carr or Dak Prescott.

The WW is barren with only Siemien, Goff and Kizer basically being left. I have only Cousins left and he has the week 5 bye with siemien.

My depth at RB is good. I could afford to anti one of them up for an upgrade at QB. Thoughts? STD league