My only pick in this year's draft is pick 12, so not likely to get a good RB there. My other RBs are pretty meh overall with Derrick Henry (and Dion Lewis), Alex Collins, Lamar Miller, Demarco Murray, and Chris Thompson.
That said, I am still leaning towards making the move for OBJ even though I am stacked at WR (Brown, Evans, Keenan Allen, Allen RObinson, TY Hilton, Edelman, Demaryius).
The starting requirements are 2 RB, 3 WR, and 1 TE with 2 flex, so being able to start 5 WRs every week makes their longevity pretty valuable.