I’m gonna have to ponder this, certainly they do seem to be related, maybe both stemming from an even older story?

I’m quite fond of those parallels, and they do have me convinced of a shared root to these stories. Problem is, how do we go about reconstructing it?

That sounds like Ovid’s version of the myth. I think that to do the type of analysis you want to do, you need to go back further, to the original version of the myth. I find that with the Greeks and Romans, over time, there are additions and changes to various myths as poets wanted to put their own stamp on things.