Pirates 'gifted' in a certain weapon?

[Captian Blimey John]

Well all the examples you cited involved sword, which I believe to be one of if not the worst weapon in the game, so that doesn't sway me much. But the differing amounts of damage can probably be explained by skill sets. The voodoo user's attacks had more skill points invested in them than the sword combos, most likely. With voodoo attacks, people doing more damage than you probably have poured 5 skill points into Spirit Mastery, Blade Instinct etc.