show me a fighting stance where you can't easily get hit in the groin when standing still and don't know how to block low kicks, which btw, muay thai fighters know.
Yes, Muay Thai fighters block kicks with their shins. Also know how to defend against teeps, every stance is going to leave some open spots. Blocking the head is top priority you can take a body shot and crack a rib but a head shot could be a knock out.