You said it in your post: running Cam is part of the game plan. He's healthy and strong. When he runs, we have one more player than a team typically does when they run the ball so why not use Cam to run the ball?
Your stats on JStew didn't consider that he shared carries with DWill. Why did you leave that out? And Rivera has said he wants one main running back for the season. I think JStew needs more help from the O line than half the backs in the league but I am happy with his production, be it slightly under par as most backs.
Tolbert contributed plenty in the Saints game so that comment came from left field. At times, he falls down for five yards. He was also wide open on the first drive on third down when Cam overthrew Olsen. There may a lot you don't see of how much potential in his position.