Noah living longer means more generations, at least on the female side, which is what the theory examines (Mitochondrial DNA).
B: How does Noah living Longer mean more generations on the female side?
(Bigdakine originally said that an old Noah means less generations. In my haste to contradict, I misspoke. I should have said: No, Noah living longer does not mean less generations.)
If females had longer fertility periods, the chance for mutation would increase. Etc.