The commonality of a man and his family being saved by building a boat and surviving a flood does point to the central origin of mankind. But, the cuneiform tablets of the Babylonian and Assyrian areas do not prove their existence of being written before the Biblical record. It probably does reflect that the view of multiple cupreous gods who fought with each other and considered man as a nuisance and a slave was a common belief as knowledge of God became degraded.
But this common belief does not support the concept of a Holy Righteous God. Only the Bible presents such a view and it can be considered to have been preserved from ancient times from Adam/Eve, Noah and then through the Jewish Prophets from the time of Abraham to Moses to Jesus Christ and the Apostles- see lineage in Luke 3 which summarizes this. The Bible continues to be preserved.
As well, God provided a way for man to be redeemed through Jesus Christ's death on the cross and resurrection from the dead-Galatians 3:12-14. He, Jesus Christ, now sits on a throne forever with God the Father-Acts 2:30; Matthew 25:31. The Holy Spirit is the Spirit of Truth and will guide a person into this Truth-John 16:13.
(See Christian Theology and Evangelism on this website for more information, and the book Defending the Faith in the Last Days listed in the bookstore on this website.)