[jacques_chester]

She mentioned somewhere that she sees India and Japan as good case studies in how modernist polytheistic societies works.

Not exact models of what a modernist Rome would look like, though. For one thing the Roman legal system, in its various forms, was a different creature. They had slavery ... but also very liberal marriage and divorce laws compared to most societies in history.

They're also one of only two legal systems which developed torts -- in Roman law, delicts. As an innovation torts/delicts take a lot of pressure off the state to provide regulation of commercial and personal behaviour, because a lot of it is then handled at the lower level by individuals and companies.