Still pirates are considered rogues and a subtype of which being assassins, ninja are specifically japanese farmers or laborers who were being repressed by samurai. And who at night would use cheep 4 sided blades called shurikan to kill samurai, samurai masters, or corrupt nobility... ninja were fair and just farmers and laborers... the average pirate is just as corrupt and swayed by gold as the nobility and samurai that the ninja slew which leads me to say past present or future both pirate and ninja ideology's would stay roughly the same.... ps history is cool and is a good judge of human psycho-social patterns. Knowing stuff like this will help flush out your pirate act which is very good by the way