Paul and Barnabas (in case you're not too sure, these guys were NOT 'circuit overseers') put experienced men in charge of teaching in congregations.
They could do this because there was .... no 'Governing Body'.
I think this is an interesting development because, in a weird way, it returns some power back to the CO's. If I understand the process correctly, the elder body would recommend someone for a position to the CO. He would then give his approval - or not - to the branch. They would then make it official.
Perhaps another way of looking at this 'adjustment' is to realize the the elders will no longer have a say-so. This pulls another autonomous freedom away from every congregation.
First it was ownership of the Kingdom Hall. Now it's the loss of control of the congregation's bank account. Next the elder body can no longer make localized decisions regarding it's teaching/shepherding staff.
The local elders can no longer be trusted
ginger