super_pinkey

A ninja sword can cut a pyrate sword like hot butter sweetheart. Plus I don't care if pyrates are cooler I only care for the fact that ninjas can kick pyrates ass anytime. You said it your self pyrates are drunk all the time. Being drunk decreases your abilities to fight. Your reflexes are reduced your speed your perception etc etc... Plus ninjas are way more trained for combat and stealth while pyrates are just drunk dudes that steal other ships and kill people.

Oh and by the way I forgot to mention that pyrates kill ppeople only with guns and in rare ocasions when the victim is unabled or hevily injured or tied with ropes and stuff, then they use their swords.
A ninja in the other hand can kill a dozen of well trained wariors by his own with his bare hands without using any other weapon such as swords or especialy guns (guns are for the weak and foolish)
(ok thats not a ninja but its the closest thing I could find now)