I know the response is late, and you are probably not in USAREC anymore.
USAREC hold its SAMC Board once a year, where as the rest of the Army holds the board quarterly.
So the selection process is strict, being told to attend the SAMC Board with 2 weeks notice is not much of an excuse because Recruiters have a whole year to prepare for it. If you just arrived to USAREC, that means your leadership believes that you still retain knowledge from the regular Army. Either way, lets not make excuses and execute.
The first Board is a mock board at your Company, or Center with only 2 weeks notice.
2nd Board is at Battalion level a few days later to ensure your commitment.
3rd Board, you will fly to your Brigade 3 weeks later. Each Brigade is slotted a set number from USAREC (10-12), so it is a tough selection and they do look for potential inductee's.
1 Month later you will fly out to the USAREC SAMC Board and compete with either a Westcoast/Eastcoast or USAREC in whole depending on the command at the time. So there could possibly be 70 NCO's or 140 NCO's at the final board.
To answer you question in short; Yes, it is because you are in USAREC. Holding this many boards just ensures the selection of NCO's is highest of qualities that is present, and also re-enforces board presentations as well as results.
I am attending the USAREC SAMC Board in the first week of April and I am just speaking out of recent experiences.
I hope this sheds some light on recruiters in USAREC interested in the SAMC Board.