“So I dont get how earlier versions or names in different languages (or changed in order to make cultural claims) cast doubt?”
Because it means the story is not Jewish or Christian but was borrowed/co-opted during the Jewish captivity in Babylon.
It would then validate Sumerian and Babylonian Gods, not the Judaic God. It would mean the early Jews were just stealing it and making it up as they went along.
No, it would validate history. If the event happened, it happened. The bible says the flood killed everyone except Noah's family, which means everyone is descended from them, so you would expect the story to pass down through the various languages and nations that sprang from them.
And if you believe that the flood was widespread but local, like for example the Black Sea region or the Persian Gulf region, it still obviously was a tremendous cataclysm that other nations would have heard of, and would have themselves been affected by. So again, you would expect the story to be embedded in the mythology of many nations in that region.
Remember, the Israelites didn't exist as a people until after Abraham, who was Sumerian. His tribe was gathered from other Sumerians and from among Canaanites.
If the cataclysm was caused by something world-wide, you would expect to see something similar even in mythologies of nations on the other side of the globe, and indeed you do.
So that means if you post something, I can’t post later my version of the same thing without stealing it from you and making up any details that differ from your version?
It would then validate Sumerian and Babylonian Gods, not the Judaic God. It would mean the early Jews were just stealing it and making it up as they went along.”
Nope, Nope, and Nope.
It just means that people from that region kept some of their history, and passed it along. It doesn't validate or invalidate Sumerian or Babylonian gods, either. It just shows continuity. IIRC, Father Abraham was from the region where the Utnapishtim/Noah story comes from, so it doesn't mean the Jews stole anything, either. It's family history.