Thanks for commenting too; it is nice to have discussions like this.
I guess my point is that the rules of an anarchist society come about from need, whereas the rules for a communist society seem planned (with some regional specifics). I agree that law comes from the state.
And I like the idea about the two form being more defined by previously stood power structures, and the examples of more liberated groups/societies of which I'm thinking off the top of my head now, all came from eroded powers (Republic of Venice, for example). Nice to contemplate.