Have you talked to any anarchists directly about this?

I can try to paraphrase, but it'd really be better to get the info from a primary source, or at least a secondary source.

The idea is that people generally think that living under ganglords would be bad. When thugs come in and try to shake down the people, the people would spontaniously bond together to deal with the aggressors. So in a sense, it is gang rule, but the gangs would only exist for moments, when needed, then everyone would just go back to doing their own thing.

It centers around the idea that everyone will do what's in their best interest and forming gangs to kill one another really isn't, nor is accepting gang rule (in the traditional sense).

I'm not supporting their philosophy, just explaining it as best I understand it.

Also, most the replies here seem to be mainly from people who oppose anarchism without having actually talked to any anarchist, so those replies hold no weight in my mind, but everyone is entitled to their own opinion, no matter how well informed.