I don't think it's a flaw, if the system is intended to be that way. So, for instance, I spend maybe 10% (that's probably a gross exaggeration) of my time teaching anything weapon-related. Compare that to Kali, and none of my students (nor me) would fare well against almost any of them with weapons. But that's not a flaw of my approach - it's the intent. Mine is intended to be empty-hand focused, with some rudimentary weapons work to give a base for using them. It's not intended to create experts - I don't have the time to teach to that level (even if I was at that level, myself). Same for the groundwork I teach. If someone wants to develop expertise in groundwork, I'd suggest they add BJJ or wrestling to their training. If they want expertise in weapons, they need to train someplace that focuses much more on weapons.