I say pirates win on coolness because they have their own language. "Arrgh, shiver me timbers! ye scurvy scum will walk tha plank! I'll send ye to Davy Jones' grave."
I have plans for a great Pirate RPG with multiple port cities and bording craft and swashbuckling and piracy. My first character will be a bawdy wench at a port who'll make money for my second character, a pirate, who'll own his own galleon and be the scourge of the Spanish fleet.
The expansion pack will bring in ninjas. Ninjas rule pirates on land, particluarly since pirates' first stop (to regain health, etc) on land is to the tavern, then the house of ill repute (where they'll meet up with my first char). So the ninjas will own the drunken pirates. On ship, though, the ninjas will get scurvy and they'll get seasick. If they try to board another ship, they might fall overboard. Their health will decrease because they will shun their daily ration of rum.
What do you think?