I apologize you couldn’t find the answer to your question from my comment, and thus thought I was dodging it. I tried to explain it in the way that I see it. In my eyes I answered your question clearly, but I will try to be even clearer on my second try.
(hopefully this doesn’t come off as patronizing)

I would also like to know what were the pedantics that you identified in my comment. If it was the final statement then that was my attempt to bring humor into the argument and wasn’t in any way meant seriously. Perhaps I should have used /j

To get to your question (and hopefully answer it more clearly). An anarchist society forms when anarchists come together to create a society. If someone with guns came to destroy that society the anarchists would defend themselves. If one of the anarchists turns their gun against their comrades the others would respond in kind. If they don’t the person takes power and the system stops being anarchistic.

Or to put it even more simply: In an anarchist society everyone is policing and protecting everyone else.