Actually both the Byzantine and Alexandrian textforms are Greek. And Jeremiah, the Old Testament Prophet, wrote in Hebrew, not Greek.
The Dead Sea Scrolls (qumran manuscripts) are Hebrew (Or Aramaic written using Hebrew orthography) and have nothing to do with the Greek textforms under discussion.
The Alexandrian textform bears that name due to its being associated with the great Egyptian university at Alexandria. However, prior to the 8th century AD the language of Egypt was not Greek, but Coptic.
The Byzantine textform, on the other hand bears its name due to its being associated with the Byzantine Empire where Greek was the national language.
And even today, the Patriarchal Text of the Greek Orthodox Church is Byzantine in character.
Who better to know the most accurate Greek text then those whose daily language is Greek?