Sometimes LOAs are given to candidates that are applying to multiple SA's and they want the candidate not to jump ship and accept an appt from another SA.
I don't think so. I don't think the academies share this information. Some candidates receive LOA's to every academy - this is indicative of the quality of the candidate and not the fact that the academies are competing against each other.
IMO - you all should forget about getting an LOA - as the nomination process draws closer it won't matter. Put all your effort now into receiving a nomination. Remember - if you are a qualifed candidate and the top of the nomination slate then you get an appointment!