I'm confused by the distinctions you drew. In the past the staff has mentioned they want one guy to get the bulk of the carries and referenced Steven Jackson. He was of course a workhouse and a between the tackles type runner, but he was also fast and could run outside the tackles and was at least serviceable catching the ball. I think that's what they're a looking for, ideally, and if one wants to call that an RB or an IB I don't think there is a difference.
They seem to be more committed to having that one guy than, say, having one guy like Cross who can run between the tackles and a third down/scatback like Newby. I don't know why they aren't crazy about rotation and situational substitutions, but that is the sense I get. It also fits the mold of who they've recruited thus far in Ozigbo and Bryant.
Are you considering IBs to be smaller, shiftier guys ala Wilbon and Newby? If so, why that? At least for Nebraska, the term I-Back connotes a between the tackle runner like Lawrence Phillips, Mike Rozier, or Ahman Green - guys who were bigger but could clearly get outside and could have caught a pass, but who were runners first and foremost. IBs are workhorses, unlike an APB who is typically a jack of all trades and perhaps a master of none except doing well in open space, and not the type you'd want to give the rock 25 times a game.
Agree or disagree?