What is there to discuss? There will always be top-tier players able to do things that the overwhelming majority of the playerbase have no chance at doing. It's happened in practically every game to ever exist. FF1 *has* been beaten with a party of only white mages (heck, it's been beaten with a *solo* white mage). FF9 has been beaten with all characters still at Level 1. There's an entire community dedicated to "speedrunning" games. Those feats are all impressive. They also mean absolutely nothing when it comes to the "design" of the game itself, because they're nowhere near the typical experience of normal players.

In a case like this, throw a DF group together into M4S (or any of the Arcadion fights) without a healer and watch what happens. What the "elite" can do isn't even worth discussing outside of a "congratulations to them."