It is important to note,the scholarship is assigned to a unit when it is awarded, based upon your DS' rankings of his schools. So, if the scholarship is awarded on an early board, say in Sept or Oct, it would be assigned to a unit at that time, before your DS has been accepted to the school. If your DS does not end up getting in to the school where the scholarship is assigned, he will have to transfer the scholarship to another school. Once the scholarship is awarded and assigned, the five schools he listed no longer mean anything. He can request to have his scholarship transferred to any school with an NROTC program, even if he did not list it on his original application.
This is where what @USMAROTCFamily
talked about comes into play. Say, for example, your DS is awarded a scholarship and it is assigned to his #1 school, but he ends up not getting into that school. He would then have to request the scholarship be transferred to another school where he did get in. The later in the process this occurs, the more likely a program may be full and your DS would have to move down his list. Some on here advocate listing a "safety" school as the #1 choice. Others advocate listing your schools in the order of where you really want to do. This is what my DS did last year and it worked out for him. His scholarship was awarded early in the process and assigned to his #1 school. He was initially deferred on early action, but accepted early on during regular decision. Bottom line, it is good that he is getting his NROTC application in early and that he is applying early action.
One last thing; units may not fill up as much as they have in the past. There have been threads that the Navy is decreasing the number of 4 year scholarships awarded, but there has been no indication they are going to decrease the number of scholarship slots available at each school.