Anthony Carn
I don't see why you think it's a "massive oversimplification" I've got an ATPL with the required aircraft type rating, so has the other guy. Either one of us is capable of handling the aircraft.
I know of experienced captains who have left one airline to join another as an FO, for more money and better conditions. You don't suddenly lose your skills or experience just because you are sitting in the right hand seat.
Hugo