The trick about equality is that it leads to system where inequalities don’t exist. So we don’t need to guess ex post which systems are a result of an equal contracting.

We can measure with Pareto efficiency what is rational in general in a state of nature. It is intuitive and does not even require referring to values. It can be argued for behind the veil of ignorance or not.

But it would require a calculation about how much there is stuff in the world so it can be redistributed.