"They didn’t report being twins, but incarnated into two persons, the two of which weren’t associated by family or proximity".

Are you familiar with David Lynch's film Mulholland Drive? It's allegedly hard to understand, but that would appear to be its major theme.

What you are describing is not rare. I have some unpublished material on that theme with more examples. It's related to research on the lives of astrological twins, not genetically related ones.