rivalry between ninjas and pirates is nothing compared to the rivalry between paladins and ninjas in Final Fantasy XI. The two classes have been dueling for years over the space of "best party tank," and have regularly traded the position back and forth thanks to Square-Enix intervention.
However, it seems that with the new July update, the tank position may once again veering towards the hands of the ninja thanks to the job enhancement spotlight falling on the assassins from the east. July will be adding the new job ability "Yonin," which will increase a Ninja's enmity (hate gain, for other MMO players), critical strike rating, ninjutsu tool use and evasion, but lower their accuracy. Sounds like a tanking ability to us! (Except for perhaps that accuracy down part, but we'll look past that for now.)