Undesigned coincidences: What kind of independence?

In this methodological discussion I'm talking about what kind of independence is relevant to undesigned coincidences and about how we can know that two accounts have that kind of independence. Too many critics of the idea seem to be under the impression that only "witness separation" independence could possibly underlie any important undesigned coincidence. If the authors or speakers knew one another, if they could have talked to each other after the event, that's supposed to spell DOOM for any undesigned coincidence argument from their testimony. But matters aren't that simple. Learn here about external and internal evidence of independence and how the more we have of one kind, the less we need of the other kind. Here is one of my older videos on multiple attestation: https://www.youtube.com/watch?v=EGVlEhtv0Zo&t=5s