I was into this stuff a very long time ago and I'm not sure, even then, I had anything intelligent to say.

The overarching hypothesis IIRC is that order would emerge and be distinct from the kind of government enforced order that we have now, and it kind of presumes different starting conditions (while it's debatable how different starting conditions could be). Yet, as you say, certain incentives remain regardless of how non-coercive certain bodies of people are in principle.

For me, when I play it out long enough, the resulting order looks a lot like governments. Given different starting conditions, where educated people are initially motivated to opt in and out of jurisdictions, and favor non-coercion, there's some hope these government-like governing bodies converge on something unlike the governments we have today. And to advocates of such ideas, given enough time the non-coercive bodies of people would be so much more productive they'd out-compete coercive bodies militarily and otherwise.

That's my memory of the whole thing at least. Anyway, I know you asked a more pointed question but that's where my mind goes when we discuss details of hypothetical anarchy, because I think it's all irrelevant if we can't determine the result is different - and I can't.