My personal opinion is I’m a little wary of the whole idea. I think it is a theory, and at the end of the day, I don’t think it changes anything in your actual journey, so I would just tend to ignore the labels.
But if you’re really interested, I think it was Carla who wrote this a while ago:
And Danielle has a longer write-up as well:
It feels like when most of us talk about twin flames we are talking about the Monadic idea (which matches a lot more of the origins) and that would make that the “normal” one but terminology between TFs are always messy and complicated.