And yet another of these overt Abrahamic theist postings, complete with a bullshit "if", some ungrammatical and carefully unspecific wordfoggery, and an overall focus on personal disparagement via innuendo.
Apparently, if the reader does the work of making sense of it (except for the "post hoc" goofy, which would require too much prose to untangle), all this is supposed to suggest, by innuendo and hint and vague handwaving at generalities - without ever saying anything that could be held to reason, in other words - that only trivial or marginal differences separate those other myths from the Biblical Noachian Flood.
That is of course false (my guess for why it is not stated clearly) - examination of the various myths reveals fundamental differences, such as: not saving any animals, not bringing any women, not building a boat, not raining to cause the Flood, no rainbow, no pissed off deity involved, not happening within hundreds or thousands of years of the same time, not global, doesn't kill everybody else, and so forth. The two myths mentioned specifically - Aztec and Mayan - exhibit some of these differences - both from the Noachian Flood and from each other.
So flood myths are common? snake myths are common, monster myths are common, talking animal myths are common, magic fruit myths are common, and myths involving large soaring birds or giants or bears or clever canids or very tall trees or women turning into things are common. Lots of cultures have David and Goliath type stories, despised castout making good in the King's service stories, wise man befriended by large predator stories,
where do you think the writers of the Bible got their material?