It would be easier to let AnComs off the hook for the actions of the state if there were examples of communist societies that were not underwritten by state violence...
As you said, it goes both ways. I'm currently on the team with the lowest democide body count (IMO).
Funny thing is, there are quite a few interesting examples of anarchist communities of various forms (see wikipedia), but Statists argue they don't count because they aren't on a large enough scale. I think the Internet and decentralization has changed the game, however, because for the first time ever, networks can be more efficient than hierarchies. That's an amazing thing! What's even more interesting to note is how the origin of the Internet combines so many different world views. Statists argue government involvement created it. AnComs might site the importance of open-source and free software which runs it all. AnCaps could then point out how the commercialization of the Internet is what actually caused it to grow and solve the last mile problem into people's homes.
Moral of the story: we should probably all be a little less dogmatic as we increase our wisdom and experience. :)