2 RBs and 1 FLEX

Which guys should I start?
These are the guys I’ve got plugged in now but should I make any changes? I like Sterling Shepard but with Smith under center, I feel like his value decreases. What do y’all think?
T. Coleman
A. Collins
C. McCaffery

Bench:
L. Blount
M. Sanu
S. Shepard