In an ideal situation this would be the case. A veteran at number 2 and a young prospect number 3. Realistically both are practice squad players at this point in their careers.
The truth is this season is more or less over if Carr gets hurt for any length of time. Might as well see what one of the young guys can do if that happens. Frankly, I don't think there was an available veteran QB out there that was likely to do much better and maybe you strike gold with Haener or Rattler.