Caveat- just a parent of a cadet.... talk to your MALO or admissions rep for an official answer!
That said, there's much confusion on this subject, but one clear answer:
Do not speculate- you need to apply to all nom sources you are eligible for!!!!
1) Most MOC's ask who else you have applied for, and it's often viewed negatively if you did not apply to all
2) USMA will know who you have applied for, and it can be viewed negatively (We were told)
3) The MOC's need flexibility if coordinating noms. (Our senators coordinate)
4) You need to give USMA the most flexibility in finding a workable slate in case you get an LOA. (and sometimes if not)
Here's the part that most get confused about:
You have to be "nominated" (IE: on a slate if MOC uses competitive method) by one of your MOC's.
But USMA does not have to "charge" the nom to the MOC. IE: LOA holders are usually "freebies". So all other things being equal, MOC's like to have LOA holders on their slate as they are the sure thing in most cases. (at least by that point)
My understanding is that USMA and MOC's will work together if needed to make things work. IE: Your nom may come from your other senator if that allows the LOA's & noms to work out better.
WCS factors in as well, depending on the nom method used by the MOC. (from memory)
So an individual MOC could have several "appointees" in one year- 2 charged to them, and the remaining as LOA holders. One of our Senators had 7 USMA appointees this year, if I recall! I'd have to dig to confirm, but from memory, it theoretically could be 10, as that's the slate size for competitive method.
But all had to be "nominated" on the slate in some form.
What's less clear is where the non-charged "slots" come from. I've seen an explanation, but would have to dig to find it. But ultimately, it boils down the allowable size of the corps, and the targeted size this year.
Can an LOA holder get an appointment without MOC or other nom? Potentially, superintendent nom, etc. But those are normally reserved for recruiting, etc.
Can an LOA holder not get a nom, and thus not an appointment? We were told it happens just about every year.
So speculation & curiosity aside.... you have to fight for every nom app just as if you did not have or expect an LOA! Do not risk it!