"The structure in the 1st Century was broadly like the JWs today"
Not really, not in regard to CO's. Paul did not go to a Governing Body to get an assignment. After his conversion he went immediately to the congregations without consulting with some head organisation. He did not go to Rome and the GB till a number of years after his conversion. Holy Spirit guided Christians, not men.
I once 'advised' the WTS on a CO. We had a self opinionated CO that would go at least half an hour overtime every meeting. I sent an anonymous (yes gutless) letter saying that everything he made mockery of everything he said about following the Organisation when he could not follow a simple instruction such as timing himself. I don't know if he ever was spoken to about it.