There is no reason to believe that Tony Romo will stay healthy, considering the issues he has had the past 5-6 seasons. RGIII would have a legitimate shot at starting a lot of games.
I agree, there is no way they sign him and draft a QB with the #4 pick overall. I suppose there is a chance they decide to pass on drafting a QB and go defense or even RB with the pick. They get a backup that is pretty young and a legitimate franchise back.
However, if it were me, I would go with taking the QB in the draft. I just don't see a rosy relationship between Garrett and Griffin for some reason. I think Garrett wants to cultivate his own guy.