By your definition then every little part of “Amazon” is technically a separate “company” including every geo. For the purposes of the discussion at hand they’re all the same. Amazon PXT and finance is the same team as AWS PXT and finance.
No. My definition is Amazon's actual organization chart as a holding. AWS is an independent first-level branch of direct reports of Andy Jassy, who was AWS's CEO before replacing Bezos. A similar branch is Worldwide Consumer, which groups what you think Amazon actually is, which means the online store, prime, books, devices, etc.