As I tell the USNA mids we sponsor, and am seconded by my USNA grad DH, no one cares about the source of your commission, as long as you deliver performance, performance, performance.
Very generally, the SA grads usually have a better professional military edge immediately after commissioning, given their 4 years of immersion and their daily exposure to military routine, culture, experiences and a wide variety of officers and enlisted leaders from various backgrounds.
Again very generally, ROTC grads tend to have a better grasp of life skills such as living in apartments, dealing with rent and bills, “civilian life stuff.” They very quickly catch up in the military stuff.
ROTC and OCS/OTS grads bring just as many smarts, drive and leadership ability to the table, and the diversity of commissioning backgrounds ensures a powerful basis for cross-pollination of innovation and ideas.
Every CO, regardless of commissioning source, will talk about crappy JOs, and they come from every source. Ditto great JOs.
SA grads do have that unique and powerful school, class and cross-SA bond, which is lifelong, and is a great resource for mentorship and for career-building in and out of the military. The SAs have the Service Academy Career Conference (SACC) - google it - which is an unparalleled career transition tool. Your ROTC son will have plenty of resources when he transitions, never fear, just not SACC. I have good friends from my college days, but more powerful bonds with my OCS classmates. We all went to work for the same “company,” similar to SA grads.
Which son is senior? This is a fun question, which they are probably clueless about. At this stage of their careers, it’s administrivia. I am sure the Army assigns some kind of precedence number to everyone commissioned on the same day. In the Navy, my “lineal number” was assigned based on my commissioning date and my OCS class standing. The lower the number, the higher my precedence, or seniority, compared to other officers of the same rank. I was commissioned in January at OCS. My lineal number was lower, hence I was senior, to all Navy ensigns commissioned at USNA, NROTC, OCS or other direct commission programs after that date, and senior to those who ranked lower than I in my OCS class. At USNA, the lineal numbers are assigned from top of class down. If USNA and NROTC are commissioned same day, I’m betting lineal numbers for NROTC are assigned after last USNA number. This doesn’t amount to a hill of beans for officers in the same grade until years later. In the Navy, if you have two ship’s COs, same rank, nested abreast at the pier, the CO with the lower lineal number, the technical senior, will rate the more desirable inboard berth! They could be 1 number apart. As I said, administrivia, though it could come into play for promotions way way down the road, when lines are drawn for promotion zones with a rank.