411A
Your example brings up the possibility of 3 Captains on the beloved Tri-Star!! If there is any worse than 2 Captains, it would be 3. I find it easier to fly with a distinct Capt F/O arrangement. Two Captains and, it seems, each is mentally second guessing the other. If there is anything worse than a Captain who has never been an F/O, it is a F/O who has never been a Captain.