One thing that does sound different at NWA from Delta. Since your have flights with 1 Captain and 3 FO's it sounds like FO's can occupy the Captains seat for TO and Landing. If you split the TO and Landing between crews. At Delta the FO's even though type rated can't occupy the left seat. In another weird thing the CA can never occupy the FO seat unless he has had dual seat training which is not normal unless you are a check airman.
Nah, the real captain has to be in the seat for TO and Landing. Just end the breaks early enough to give him time to hop back in the seat and do a changeover and approach brief and look at the WX etc etc. or start the break shortly after level off when the CA is comfortable with the situation at cruise.