The terrain of Afghanistan makes it very easy to swallow large formations, so you have a point about the numbers. However, we never needed those numbers because we already had them. We just needed reliable numbers, not Afghans who could be bought off by al-Qa'ida money men.
A battalion of Rangers dispersed into platoon or squad sized elements and co-located with the large Afghan militia forces would have put U.S. eyes all over the valley. Maybe not enough to prevent a breakout, but enough to say which way they went and to conduct pursuit.
As it was, our Afghan allies pretty much shrugged and said, "They got away". And they did.
At least give me the point about the possibly imaginary covert CIA guy.