Of course both topics are completely relevant to this thread. When comparing X to Y one needs to examine both X and Y doesn't one ? The author or scientists endeavor to explain that the flood they are examining matches the Noah story. In order to make that examination both need to be examined. In examining the Noah story it is very relevant whether the text is supposed to be completely literal or metaphorical.
You are making a claim that its reasonable from a scientific point of view that we can compare X to Y without examining X because X has religious significance. I will propose to you that your claim that we can compare X to Y wihout examining X lacks any scientific merit and might be considered by most folks as silly.
And I am pointing out that any claim that the text is completely literaly immediately takes you into the realm of mythology, not science.
There is not one chance in a gazillion that the bible is 'the unerring word of god', in my opinion.
I don't believe the myth of biblical accuracy, so when you use that myth as 'evidence' for something I have nothing else left to add to the discussion. You're now discussing mythology, not archaeology or science.
So other than some story written about the event by men 6,000 years later, do you have any comment about the flood the story mentions?