I haven't argued any such thing. Your two proposals are not the only options. I can easily think of several others. My personal belief, which I have not made any attempt to argue for, is that the flood story is meant to describe man's relation to God, and that the story need not be true to accomplish that goal.
Of course it is that too.
It is a divinely revealed piece of information that corresponds one-to-one with the extinction of all other kinds of men that os=ccurred 40 thousand years ago.
That coorespondence is no coincidence.
The previous chapters in Genesis, 4, and 5, tell us of the 22 previous humanoids that actually correspond to those 22 now extinct humans which is also factually true.
This is no coincidence either.
Genesis tells us that there was hybridizations before the "flood of modern man Out-of-Africa."
That too is true, since we all carry the genes of Neanderthal man today.
That is no coincidence.
The whole tale corresponds directly with what science is telling us today.
The ONLY axiom needed in order to see the two stories are one and the same is to understand the necessity for writing the tale in analogy to water instead of people.
It is no coincidence that the mention of the Ark refers to the skull of Modern man which contained the visions of all the animals nd carried them into the New Heaven and New Earth that began 40,000 years ago for us, the sons of God to come.
The ONLY possible "Ark" that could carry all the animals into this new world of Modern man was our own skull:
That is why Moses continued this tale: