ROS Back up RBs

I need another rb on my bench

My current rbs
Zeke
Barkley
Singleterry
Hunt

On waivers
AP
Miles Sanders
James White
Guice
Ty Johnson
Mattison
Duke Johnson

WRs on bench
Hilton
Samuel
Gallup

In a standard league - who’s best to drop and pick up!? Or just stay with four I have!?
It’s 1 qb 2 Wr 2 rb flex

Usually play with 3 rbs when possible