I'm sorry, could you unpack your point a bit more? I'm not even sure where he made an argument in that post, let alone "defeated a straw man". It's mostly just musings.

Are you perhaps misinterpreting his post as a question of how far the state can be pared down (given your second paragraph)? Because that's not the question; the issue of government size is nearly tangential and just parenthetically touched on. The question is the minimum size a society can be at our scale of sophistication. One could then speculate about how "governmenty" that society would be but that's really a separate question.

This is really an engineering question, not a political one. Since we're asking about the minimum, we're pretty much assuming that the component people have the optimal organization and the exact details of that organization don't matter to the answer much.