I’ve independently had the same question. There are a lot of assumptions in our contemporary cannon that are unchecked (afaik, but open to being told I don’t know what I’m talking about since this is by no means my area of expertise).

It may even be the case that this isn’t possible to know, at least given the evidence at hand. Theories should simply take note of this ambiguity, by qualifying with “if X is the case, that means theory Y is true”