Dowdle has been no more than a backup in the pros, and I see no reason to expect that to change. And Dallas may be going cheaper overall at the position, but Elliott is making more, $1.6 million of it is guaranteed and he has incentives built in.
Week 1, who gets the start and why?
Wait, the question was who am I starting. I think it would still be Elliott because Rico hasn't proven he can be a starter. I'd give him every chance to prove it in the preseason, though.
With what we've got, I'd start off limiting Elliott to 12 to 15 carries per game and give Rico and Freeman about 10 (who gets them would change based on who is doing the most with them). Any other carries would go to Lamb, Turpin and/or Luepke. I'm expecting Vaughn to end up on the practice squad, but I could see him getting kept over either Dowdle or Freeman if he shows the ability to be a change-up back/ long third-down back.