Josh will be just fine. If they don't draft Murray, that will not only be a huge vote confidence for Josh, but all he will need in going forward.
If they do draft Murray, maybe it's only that they haven't gotten the haul they were seeing if they could get for that pick. There also the same anticipation over trading Josh or not. They're in a very unusual and complex situation, and most likely simply have no idea what might be presented to them at the last minute in regards to both the pick and Josh. I would guess they actually don't know and smartly are keeping the doors open.
I don't think the Cards, Murray, or Rosen can lose just being patient. It's just a matter of how much the Cards can milk thus situation for by waiting it out.