It is true that Navy-Marine Corps ROTC commission the most pilots?
Yes, by far. This is true of all aircraft. For the graduating class of 1997 and 1998, all physically qualified midshipmen interested in aviation were selected. Please compare that to our AFROTC counterparts. You see, the Air Force selects a large majority of their pilot slots from the Air Force Academy, leaving far less for ROTC units. In the Navy, you chances of receiving a flight slot are the same whether commissioned from USNA or a NROTC Institution.