I don't know, but . . .

I was chasing rabbits while learning about the Deuterocanonical books, and ran across something I'd not heard of before in the Dead Sea scrolls: most of the scrolls of scripture were "proto-masoretic" but some reflected the Septuagint. There seem to have been several variant textual traditions (not different in substance, but in details -- and generally not major details either), and the Alexandrian scholars seem to have picked one to translate into Greek. A few centuries later Jews converged on the Masoretic text as definitive. (With, germane to my interest here, the Deuterocanonicals omitted as not having been written in Hebrew but Greek. Which, for some of them at least, the Dead Sea scrolls show to be an incorrect assumption.)

Why the change in preferred texts? Some early Christian writers accused the Jews of removing books and concentrating on a variant that provided less support to Christianity. I can imagine them preferring "a young girl shall conceive" over "a virgin shall conceive" for that reason, but I don't see that Tobit is all that supportive of Christianity. In fact I've read that the Orthodox accept the Deuterocanonicals as canonical, but as "second-class" as far as supporting doctrine.

Wikipedia claims that "Very few manuscripts are said to have survived the destruction of Jerusalem in 70 CE." That's suggestive.

If the scholars in Alexandria decided on the "proto-septuagint" variant manuscripts as being the best, they'd have collected as many as possible to provide the translators with their material. In a land without printing presses, there might not have been a lot of them to begin with -- though synagogues should have had a copy of the Torah, so there should have been a lot of those.

Which manuscript tradition to pick might therefore have been based on geography -- what was available locally. Translators mentioned in the link above were in modern Turkey and Greece, not Egypt. If the Alexandrians snarfed up most of the proto-septuagint types for their translation project, that would leave the rest for everybody else. The Dead Sea scrolls were proto-masoretic over proto-septuagint by 12 to 1. (A looser version made up 20%, and others 15%.)

My own take on the Deuterocanonicals from years ago was that they were mostly harmless, and sometimes wise, though here and there (perhaps translation issues?) were some things that don't fit well with the gospel (a daughter is a loss?).