As far as toy universes went at some point I said the figures I had were the total of Cobra. Yeah, that may have been as little as 2 dozen guys at one point. It didn't matter since my toy universe wasn't based on the real world at all.

In the popular media, I imagine membership/troop strength has fluctuated over the years. From grassroots movement of hard core fanatics to a larger more bureaucratic organization of international malcontents, mercs, thugs, etc.

I'd probably say that armed forces are outnumbered by agents, operatives, etc...since where would armies be but cobra island and a few hidden bases. And Cobra Island isn't that big to support, even house, thousands of people.