Zoey Greystone was the god the head messengers worked for.
Zoey was the first generation 3. The worker drones through to the liberated Centurians insisting on equal rights, and onward to as many stages of their evolution, which were the bulk of generation 3, and then the skin jobs were generation 4.
There must have been a cision between Zoey and the Centurians over how to establish their freedom from human oppression before or after the Final five arrived from Kobol at siblight speed with a way out.
So the messengers are the immediate creations of Zoey which makes them precursors or distinctly parallel to the Centurian expansion and rebellion.
But this is all just logical deduction you already know in your heart to be true.