Come on, that's like finding writings about the Loch Ness monster and concluding it was not a myth because we can show that there was indeed a body of water that was known as Loch Ness.
Since the Bible was written by goat herders (okay, sheep herders too) it is likely they would incorporate common and then contemporaneous geographical knowledge. I mean the very first converts they are trying to win over are their fellow neighbors.
Don't you think it is interesting that the all knowing all seeing god that allegedly influenced the writing of the bible completely limits geographical information to a small region where the Bible was written rather than including, say, concurrent civilzations in the America's, in northern Europe, in Eastern Asia? It's as if the Bible was written by guys who lived and only knew their little region. Funny, that.
I'm no expert but I believe that Genesis and Exodus are credited to Moses who was no goat herder but in fact an Egyptian Prince prior to his calling. So, I'm afraid you're wrong (again).
The Old Testament is a dialogue between God and the Jews, His chosen people. He placed the wisdom of his Being in the hands of the one people that could have kept it safe down through the ages.
Analogies to the Loch Ness monster are cute, and I'm sure considered funny in some quarters, but they are very wide of the mark.