Replying to the general topic, not Heavenly's reply.
I think one of the big issues with this sort of theoretical reductionism in these types of debates is that people who are less familiar with anarchism assume that it is a system. That it has inherent rules. That it must be consistent. That the system is the authority, as is the case with forms of government.
The paradigm is wrong. Anarchism is not a government. It is defined by the absence of authority. The answer to any reductive "what if you want to force someone to do this thing but you can't force them to do this thing" questions is the same... The answer is the same every single time: without authority.
Anarchism is not a government-without-government.
It is praxis.
You have to apply it again and again and again. And the solution will be different every time. And there will be good choices and bad choices. It is not utopia.
It's praxis, which is one thing and it is everything.