Assuming all the starters listed were injured (unrealistic scenario, obviously), I would rank them:
1. Royster: Every Redskin RB performs when given the opportunity
2. Goodson: Familiarity with the zone-blocking system and less focus on the run/swing pass game if DMC is out
3. Turbin: I don't know much about him, but the Seahawks will remain a ground-and-pound team with Lynch out
4. Dwyer: He's already shown what he could do when given the workload
5. Hillis: Chiefs are terrible this year and might have to abandon the run early and often
6. Vereen: Patriots have plent of options even if Ridley were to get hurt
7. Wilson: Giants still have Brown
8. Blount: Not an every down back and has looked very pedestrian this season
However, being realistic and taking injury probability (and other factors into account), I would probably rank them like this.
1. Goodson: Let's face it, DMC has not yet played a full season
2. Vereen: Even with Ridley playing, they can still provide a nice 1-2 punch. Belichick loves this guy and he was even named "starter" last week
3. Dwyer: Injury factor is already coming in to fruition here.
3. Hillis: Will likely take over Shaun Draughn's role, which provides potential for 10 touches a game once he's completely healthy
4. Royster: I still rank him high for the simple fact that every Redskins RB performs when given opportunity. Not to mention the Shanahanagan factor.
5. Wilson: Based on talent alone, he could surpass Brown on the depth chart over the course of the season. Injury factor with Bradshaw is high as well
6. Turbin: Purely an injury-only stash. Unless those back spasms keep Lynch out for an extended period, something else would need to happen here
7. Blount: Provides very little value now that he seemingly lost the goal line role. Also, in the event of a Martin injury, I don't see him making much of an impact.