Well the new starters don't seem to be a problem as much as the quality of starters. Harremans is a decent vet coming off an injury that year, but 70th out of 78 guards puts him in Pears and Chris Williams territory. And he's the best they acquired.
I absolutely believe that even without Dareus, Rex will be able to dominate their O-line all day with 5 rushers. With Gore still kicking, I'd want Brown in, but if we're playing Nickel/Big Nickel/ Dime all game, we still have depth in Gilmore, Darby, Graham, A. Williams, Robey and Duke/Meeks.