That is why some years all ten of his nominees have received appointments--state nominations are generally considered to be more competative than local, congressional nominations. Or, at leasts that's how it sounded.
Clarification needed here, especially since many posters will take that TX might be the same as ID or KY or WV. If the MOCs do not talk, it maybe highly likely that the list is not duplicated giving you 3 noms. Now look at VA where they do talk, that means you are probably on one list only. How is it that 10 kids from within your own district get in? The reason why is because after the slate appt goes out, the cadet can be pulled in from other sources, such as the Supt. Nothing against Idaho, but VA public hs are nationally ranked, which means their PAR will probably be higher. The NWL also goes through the point system, highest wins.
You also need to realize that some states have more military dependents, so they can come in from Presidential, states like CA, CO, TX, VA, NC, FLA, NY, MD, NJ and even AK or ID can have clusters of candidates that are in this category compared to WV, TN, PA.
On top of that scenario, typically where an SA is located many candidates are attracted to the SA from the allure.
In the end an MOC may say they have 10 constituents there for Class of XYZ, 10 for ABC, 10 DEF, and 10 for GHI however only 5 at any given time can be there charged to him, not 40. The real reason they have that many is a compliment to your state school system and to the caliber of the cadet.
As far as the cadet who left for medical conditions, that slot does not open until he is officially released. In your scenario, he is a medical turnback, if he gets medically cleared to go back, he doesn't go through the whole nom process again. He will come back as a turn back and go through more rigorous medical clearance on I-Day. Now if a cadet leaves due to the SA's demand based on academic reasons, than they are gone, thus the slot does open. The reason 2 slots can open often is due to the fact that 25% of each class do not graduate. Typical class comes in at the 1200-1300 marker, most class yrs graduate @1K marker. Figure it out 200-300 spread amongst 50 states, means every yr @6 from each state leaves on the average. The biggest bulk leave between C4C and C3C. I read somewhere at BCT @5% will leave before the 1st day of classes.