Kwd:
IMO... there is an aspect that has not been considered. (Sorta what came first - the hen or the egg).
I am not sure what you thought your quote from Kohler accomplished. It rehashed what I and some others had written.
As I said, the source of the story was the apocryphal literature (CCC said apocalyptic and Palm agreed post biblical), probably the Slavonic Book of Enoch. Sure enough, this quote from Kohler (whom you would not like at all if you knew anything about him) reaffirms that possible source. Both the Slavonic Enoch and the Slavonic Testament of Moses/Life of Adam and Eve (the same books in Greek and Latin respectively) are transmitted to us by Christianity, not Jews. These books started out as Jewish literature but were copied and recopied by Christians, much like Josephus. Although we have a copy of Enoch from the Dead Sea Scrolls, the copies referred to by Kohler are Christian products (obviously because he died 25 years before the discovery of the Dead Sea Scroll of Enoch).
So your reference to egg and hen here can be applied in ways you may not have intended. These references are in Slavonic, Christian versions of these stories.
Just a bit more about Kohler. He represented the right wing radical Reform stream of Judaism 100 years ago. He insisted that Judaism was only a religion and pushed for Jews to imitate Christianity in its outer trappings here in America. You would not have liked his extremism in which he insisted that Torah was not from Sinai but an entirely human product without divine input. He was definitely not your kind of guy. He wasn't even my kind of guy. His form of Judaism was rejected by the 1930's here in America, although vestiges of his thinking still hangs on in places.