It's an interesting situation. If one believes Dak Prescott isn't going to have the typical rookie mistakes that he's avoided so far, I guess you leave him in. But I'm not sure he's that special. So I think you put Romo in, wait til he fails and bring Dak back. Otherwise, you're waiting for Dak to fail, putting Romo in, waiting for him to fail and then putting Dak back in. That seems to be an odd way to go about picking your QB. IOW, you're waiting for failure.