Agree with Bill the Goat.
An MOC can give out a principal with ranked alternates. There is a sticky in the Noms Forum that explains the various approaches.
Whether you want to describe a slate as principal with ranked alternates or simply a ranked slate is somewhat irrelevant as, in either case, the SA must start with the first person and go down the list -- giving the appointment to the first fully qualified person on that list.
However, once that appointment is given, the others remaining on the list go into the national pool (assuming they are not on another nominating slate) and there they compete as competitive alternates.
For example: Candidate #1 on the MOC's ranked slate is medically DQ. Candidate #2 is fully qualified, as are Candidates #3-#10. The SA must appoint #2, even if they consider #5 to be the best candidate. However, once #3-#10 go into the national pool, #5 probably has a better shot at getting an "at large" appointment b/c the SA considers him/her to be the best remaining candidate on this MOC's slate.