One thing to keep in mind is that, because there is no such thing as cardinal utility, there is no way to do interpersonal utility comparisons, or make scientifically meaningful statements about the extent to which utility is maximized in one hypothetical or real society compared arithmetically to another.
What we can do, is demonstrate the singular tendency of capitalism to create general prosperity in direct variation with the degree to which it is unhampered. This is because, as I’ve said, the singular tendency of capitalism is to provide for individuals the satisfaction of their wants according to the extent of their contribution to the satisfaction of the wants of others.
Then, we can show how capitalism is unhampered (whether we are talking in regard to the production of tube socks, or the production of security) in direct variation with the extent to which a certain way of delineating property rights (which happens to be the way of delineating property rights, the violation of which deontological libertarians consider self-evidently fiendish) is adopted.
Once convinced of that, it is obvious that it is overwhelmingly likely that any given person’s interests would be better served under complete (anarcho-) capitalism than under any other social order.