The question would be who created them. Venat created the rabbits, Hermes created Meteion, so I wonder if the Twelve were created by someone like Hythlodaeus. Or maybe even Azem as a way to watch over mortals in the absence of the Ancients. That sort of fits with the Azime Steppe being named after Azem, etc. I could see someone of the Convocation creating guardians of immense power to protect mortals to a degree. After all, the Ascians are trying to save the Source, not destroy it. So as the Rejoinings will undoubtedly cause the death and suffering of many, they would need to make sure that many others survive it somehow. Hence, the Twelve. Just speculating, of course. But very interesting!