For all the SAs, reading every page, drop down and link on their websites is the essential first step. Most answers are there. I know for sure USNA has a senior enlisted member in Admissions who helps enlisted applicants, so the others probably do too. It’s a simple matter of calling Admissions and asking for the enlisted admissions rep or counselor.
Your DS, since he’s Army, has to research the applicable Army directives for his situation.
https://www.usna.edu/Admissions/Apply/Active-Duty-Service-Applicants.php
The other key is not so much the major, but which SA has the selection of officer professional communities he would be fine with going into. Most Navy roles involve being on the sea, in the sea, under the sea, or over the sea. ROTC and the SA are interim stops enroute to the period of obligated service.
Your DS should also take some time to reflect on the individual culture of each service, as well as the fact that he would be an older member of the class at, say, USNA, and he’ll be treated like the 17 year olds, by 19 year olds, plus no civilian clothes, no car, very limited off-Yard time on Saturdays. No drinking even if he’s 22. Don’t get me wrong, prior enlisted do great at USNA, and are usually a great help on all things military. It is worth comparing SA full-immersion vs. ROTC college lifestyle.
