First of all, we gotta stop accepting Sitchinite Sumerian-Hebrew version of the Genesis account... and the whole Bible for that matter. Read a specialist graduated in PhD in both languages and then you'll discover Sumerian account is quite diferente though with similarities.

Second, Moses wrote compilations of previous Works and other things were added when he died, his own death for example. Moses learned a lot from his father , going backwards in generations to Amram and so on, rewinding the tape of history in an imaginary DVD or tape if you will.

May I remind you Abraham also grew up in Sumerian land and spoke and wrote in cuneiforme language? Hence, Moses received many records whether in animal leather scrolls or tablets made of clay (inverted in the cilinders because they were a matrix of the writings done later on).

Abraham himself had a strange story suggesgting his half-sister Sara remained in pharaoh's tent. So he got in touch with Egyptian and Sumerian culture.

The revelations are similar. I encourage you to compare with the ancient writings of the Chinese who, in spite of being politeistic people, worshipping many gods, they still had the concept of a deceiver being in Eden, man being created from dust or clay and a superior unique ruler of the universe.