To be fair, if we redshirted any of these guys, I believe they would pull a Marlon Humphrey and be gone after their 3rd year anyway. Any of these freshmen backs could be the next Landon Collins or Rueben Foster on special teams. So I don't mind playing them to get them on the field sooner.
The last back I can think of with some talent who stuck around, maybe not Brian Robinson talent, was Jalston Fowler. But he also went through an injury season and maybe he didn't come in with as much fanfare, I don't remember.