Rather, documentation, and not mere opinion or rhetoric, has indeed been posted. If you expect to be successful in this spiritual war, then you will need the best spiritual weapon. For the follower of Jesus Christ, that would be the Holy Bible and not an invention (e.g. LXX).
If by Holy Bible you mean the Masoretic Text, it has many inventions in it. The Masoretes altered the Hebrew text in numerous places by incorporating their traditions (masorah) into it.
Zechariah 14:5 is a good example. By simply altering the pronunciation of a word three times in that verse (nstm) they changed its meaning from a landslide blocking up the Kidron Valley to the messiah splitting the Mt of Olives so his people could flee through it, just like Moses split the Red Sea so Israel could flee through it. Targum Jonathan to the Prophets actually adds "at the Red Sea" to the end of verse 2. There is abundant real-world evidence that the LXX version, which describes a valley being blocked up, is correct. Even the Jewish Publication Society has stopped using the MT version of that verse in some of their bibles (eg, Tanakh: The Holy Scriptures) in favor of the LXX version.