So if there were no ranks. Then maybe a male would be assumed to have seniority over the femal unless she's super-duper-obvious very superior?
What if that's how it actually works in real world. At least in some aspects and areas of life.
In my experience, this is true in a number of areas where there's a stereotype of gender-associated abilities. In technology, this was and is still true -- I used to say to friends that a man claims he's an expert in TCP/IP if he can tell you what the letters stand for, while a woman isn't considered an expert unless she can quote the RFC and tell you the packet format of every protocol in the stack. In other martial arts, I've seen beginner men instruct senior women, disparage their competencies -- the "huh, well that wouldn't work in a REAL fight" is perhaps the most frequent retort to being on the receiving end of an effective technique (with the subtext, "...and of course, since I'm male, I know how to fight!"). These are also the same guys that can never resist wandering over to the heavy bag and punching it as hard as they can. Then we get to see how stone-faced they can be, and how fast a wrist can swell up.
Summary: there's definitely a strong positive correlation between believing a lot of silly crap about other people and their abilities, and believing a lot of silly crap about yourself and your abilities.