They are allowed 5 there at a given time, slated to them, not 5 per year. So some years they have 1 vacancy, some years they may have 2 or even 3 depending on if they have had appointees leave the Academy for one reason or another. Rule of thumb is that they usually count on 1 vacancy a year. For every vacancy, they can nominate 10 candidates. They will either rank order them or submit an unranked slate and let the Academy select which nominee will get the appointment for that vacancy. Each MOC does it differently, its their choice. If you receive a nom, but are not appointed as the 1 from the slate of 10, you still have a chance at an appointment because you will then go into a qualified pool and will compete with others in the pool nationwide for the remaining slots left to fill the class. This is why you may see some districts with multiple appointees from the same slate, even though the MOC technically only had 1 vacancy. If you search this forum you will find a truck load of info on how the Noms/Appointment numbers are broken down.
Nobody can really tell you how to rank your Academies with each MOC. That depends on your desires. But what you did above makes sense.
