The whole nomination process works kind of like the Hunger Games, in the way that the more times you are entered into the raffle- the higher of a chance you have at getting selected. More nom apps= more entry chances
Also, sometimes the nom is 'awarded' to 10 people on what is called a slate, in which the nominations board sends 10 names to USNA and tells them to pick for them.
Sometimes there might be a weighted list of names as well, but works the same way as above.
Other times there is only one recipient (think rural and low applicant pool) who might have a back up candidate as well.
Or, it could be like the presidential one which a number of people recieve. I don't remember the number exactly but I believe it is on the order of 100 (?). This one as well as the VP work to check off the box- but I think they are treated a little differently.
In MD, my state, the Senators and Congressmen communicate who their chosen nominees are so that no person can be double nominated to give a larger scope of candidates a chance. Just ask your representative about their procedures- also gives you a chance to develop a relationship with the person who could help get you to USNA.