No, the Ancient Jews were immaculate about record keeping.
in fact, the Bible, outside being about Jesus, is a factual Human Being Lineage Record.
It's [Bible] also a factual Old World Map and Ancient Names keeper for modern day [Gog and Magog = Russia].
This is not just simple knowledge, by the time a Jewish boy is 13, he knows the Complete Old Testament word for word in Hebrew, like God gave it. just 1 of millions can decipher Genesis 6 like other 13 year old gentile boys can load live rounds into a chamber.
This ain't some story to the Jews, they see it alongside Genesis 3 and 12 + Deuteronomy 32 as Angels ATTACKING God's human lineage.
and because you want to pervert the Holy Word of God, you make it like they were having some sort of sexual encounter.
look at how these Nephilim are described in many places of the Bible. butt ugly, 6 fingers/toes, they looked aged and old when they were young, they are something that God clearly did not Create to represent the Human Race. these Fallen Angels, took the Beautiful Creation of Woman, how God wanted her to be, and planted seed that gave birth to Hideous Creatures. And these beasts committed so much abomination, God, KILLED them a very HORRIBLE way "Drowning/lungs full of water/choking and more water keeps filling your lungs until finally the nervous system causes sporadic body jerking and finally the soul is released from the body." God, Killed the entire World with Intent and Purpose. ...but you find it all to be sexual