Every time we talk this over, I’m a little smarter drzz. I believe you are correct, that even with some teens, seniors and women, the force would not have been greater than 2,000 of fighting age, and maybe a village of 7100 counting everybody in all bands.
http://home.comcast.net/~jbusse1/
According to my greatuncle, whose father helped cook Custer’s goose, there were relatively few Indians involved. There were only about 250 Indians that broke Custer’s attack and very probably broke the cohesiveness of his command. After that it was merely a case of the Sioux/Cheyenne running down the survivors.