Excellent posts! Sure is a breath of fresh air, considering all the crazy posts out there right now about where GRob appears on the Ram's depth chart. Which happens to be backing up Jake Long & Roger Saffold.
As far as Joseph goes, though, I don't think he factors in here... Joseph didn't beat GRob out of a spot, because RG was never considered for GRob anyways. If anything, if something were to happen to Joseph, I would think Saffold would slide over to RG & GRob would take LG. I don't recall who Joseph's backup is, but I wouldn't think they'd drag one of our depth OL's out there if they still had Saffold available to fill that gap.