The contradiction of Anarcho Communism

There are many different variants and schools of thoughts on anarchism. 

Personally, I identify with libertarian type anarchism - voluntaryism, anarcho capitalism, agorism. I even agree with many aspects of anarcho primitivism. I think all logical anarchists believe in the non aggression principle, that initiating force against peaceful people is wrong, and slavery is wrong, and that the state is a parasitic perpetrator of these things. 

However, I feel like "anarcho communism" is not only laughable, but an oxymoron. It doesn't make sense. For that type of society to function fully, you're under the assumption that 100% of the people agree to that. Otherwise, how would they deal with people who want to trade and exchange voluntarily for various types of capital? There would have to be some enforcement mechanism. And that would be a STATE. 

How do these communists intend to address small businesses that produce very specific items that are not necessarily essential to basic human needs? Speciality trades and crafts? What if there aren't enough of these people to create unions in these fields to warrant collective ownership? Do these people just abandon what they are skilled at, what they do that provides value, and go work in factories? 

The irony is that in a voluntaryist society, communists would have every right to live that way if they wanted to, in private self sustaining communities, everyone having communal ownership of the means of production of everything they'd need. As long as they didn't try to force it on the rest of everyone who wanted to trade products and services voluntarily. 

But in even a stateless, completely communist or socialist society, the voluntaryists would not have the rights they were born with. The idea would still require force.

Now don't get me wrong, I'm aware there are anarcho communists that fall under the umbrella of voluntaryism, that in fact identify with communism in the way I stated above. But it seems overwhelmingly that most an coms seem to be aggressive and unable to fully answer these questions when asked how communism would be enforced on a large scale in the absence of a state, without contradicting the core tenets of anarchism.