The chances of the ninjas being jedi and blocking bullets is quite impossible.
And according to physics the impact of a bullet against a sword/katana would most likely send a shockwave down the blade forcing the sword out of the ninjas hand.
I HAVE THE PERFECT ANSWER
ninjas(Sword) vs pirates(sword) = ninjas win
Ninjas(throwing stars) vs pirates(throwing knives) = tie
Ninjas(hand to hand) vs Pirates(hand to hand) = ninjas win
Ninjas(poison darts) vs Pirates(guns) = pirates win