“Q: How does natural law fit with Noahide Law?”– Yes, it fits. I would say that

–“Q: How does natural law fit with Noahide Law?”–

Yes, it fits. I would say that noahide law is a very simple version of natural law, or that natural law is a more precise version of noahide law. Why? Much of what we do in natural law is to try to prevent lying and baiting into hazard. Particularly by politicians, academics, pseudoscientists, and false prophets. And the rest is to solve more complex questions as the complexity of the world increases.