“Also, even though the combine has 3593 "active" members, I think that only about 3000 are really active. ”
What do you mean by this? The active member count refers to the total number of players who have logged in during the past week only.
This means that count is constantly changing -- one player may not log in for a week, and another will begin to log back in, for example. The net count changes very little, in such a situation, but technically there are twice as many people logging in over a period of two weeks (again, just an example; for sure it is not quite that high).