I get the argument that Utah hasn't proven when they bring in a QB that they succeed (Williams wasn't bad), not the same with RBs. Bernard was a solid backup to TJ but who wouldn't back him up? That said, Pledger and Curry look very solid and looking at what Utah got out of Booker, White, and Williams I think Utah gets the benefit of the doubt.
This also proves that Phil looks at something more than experience since none of these guys have a ton of that.