Well.... The rule for something like that is generally "if it makes the story awesome, it's okay" - not quite rule of cool or rule of funny, but rule of narrative imperative, perhaps? In which case, kryptonian/daxamite absurdity is, while not, probably, objectively any more ridiculous and impossible than this "one sex then the other" nonsense, infinitely more okay, because the "battle of the sexes" crap here is not just unnecessary but actively dragging the plot down in quality.