Could the "Great Flood" have been a political purge by Adam (Gilgamesh's) father Lugalbunda in an attempt to obscure other's claim to Gilgamesh's throne? And the tale we know today is just what Lugalbunda told people what happened?
The "messangers" of God just being ancient hermetics who served the priest king Lugalbunda by ferrying messages to his allies across his kingdom.
But once Lugalbunda expected to die, he wanted his son Adam who was "dirt" (uneducated) compared to those with "Fire" (Lugalbunda's contemporaries, generals, family, etc).