you know what's weird? in the initial scenes, when lion-o is still the size of kit and kat, they (kit and kat) are allowed to join the fight when the ship is attacked by mutants while lion-o is told he is too young.
but again, they are treated like kids and act like kids. probably just a small plot-hole in the toon. something explained in the comics that maybe they forgot about or ignored in the toon. /shrug