GL Tirebiter: Since much of it (the Pentatuch) predates a written Hebrew language,
Good point! It demolishs the Watchtower's construction of a narrative in which Genesis becomes a series of summaries of individual histories whose authenticity is guaranteed by divine authority. It may be that, but it cannot have been written by any eyewitness because there was no known writing system in existence.
Here's a timeline for writing systems:
Quote: "According to contemporary scholars, the original Hebrew script developed alongside others in the region (the region is the Land of Cannan and Arabia) during the course of the late second and first millennia BCE; it is closely related to the Phoenician script, which itself probably gave rise to the use of alphabetic writing in Greece (Greek)." (See: https://en.wikipedia.org/wiki/History_of_the_Hebrew_alphabet )
All of which casts doubts on the story of YHWH personally writing in Hebrew the ten commandments on tablets of stone.
And if Moses then wrote Exodus, Numbers, Leviticus, Deuteronomy, what writing system did he use? Egyptian pictographs? How ironic that would be.
GL Tirebiter: the Master Copy was an oral tradition. It was transcribed after the fact.
An oral tradition of the Pentateuch cannot be called a Master copy.