Need some advice

Hey I need some help on who to start for a couple of positions(flex and my number 2 running back). This is also a ppr league.

So I'm starting MJD in one rb position. Then for the next one and my flex I have these guys:

Kevin Smith vs Minnesota
Joseph Addai @ Miami
Fred Jackson vs Tampa Bay
Earl Bennet vs Pitt
Justin Gage vs Houston

As you can see most of my backs are playing against pretty good defenses so it doesn't really help. I'm still thinking of starting Kevin Smith though in one of the positions and then Fred Jackson in the other. What you guys think?

Gage and Addai