How do I configure Fusion Contract Manufacturing for a sequence of Contract Manufacturers?

How do I configure a supply chain for Cloud Contract Manufacturing which includes multiple separate contract manufacturers and ends with a distribution 3PL;

OEM (contracting company which holds no material)→CMO(bulk product manufacturer)→CPO(finished product packager)→3PL(distribution warehouse)

Which are inventory orgs are configured as "External" rather than "Internal"?

What sourcing rules are required?

Where is demand applied?