Yes, that would make sense in the real world but not so much in the Naruto world. The potential in Naruto is much bigger and more varied than in real life (or real history), thus also making weaknesses more pronounced. I suppose the only relevant real life comparison would have been to forbid students from learning any weapon handling. After all, a decent man with a sword can still beat an excellent unarmed man, thus creating a weakness somewhat equal to those shown in this episode.

And, well, I suppose it's getting a moot point by everything we have seen, but these fellows aren't supposed to be honourable martial artists but ninjas... For a ninja completing the mission succesfully should be more important than staying pure in your teachings and techniques.