Make it so!
I thought about the duel wield, but if you are a pirate on a ship, you want to have a hand free to catch on to ropes and the like, so a single weapon is probably best, maybe the Wakizashi with the harpoon, or the Ninjato with Harpoon.
If we take off the No-dachi from the Wokou, I would like to move it to the Attendent with the sword then, if that makes sense?