Libertarians get lost in introspection. The central problem of creating an anarchic society is fully articulating property rights such that they are possible to rationally adjudicate under the common law.
It is this rational ability to adjudicate differences under the common law that makes possible ‘rule of law’. Without such rational articulation, rule by man’s discretion is necessary.
The sufficiency of that articulated list of property is what determines if transaction costs are low enough that it’s rational for people to voluntarily join a polity in which plans can be made, and disputes can be resolved, according to that list of property rights.
As I have written recently, libertarians (foolishly) discount these transaction costs because they tend to be above, and interact above, the threshold at which moral behavior is dominant.
The NAP is either an insufficient test, or private property rights that are intersubjectively verifiable are an insufficient scope. Propertarianism extends property to that which people demonstrate they believe is their just property, and places the burden on the individuals with the greater knowledge. “Seller Beware”.