Um, as for the "Ninja Sword," I've read that these technically didn't exist. They either used modified farm tools (most common), or--if they were VERY lucky-- a samurai weapon such as a katana.
For the game, I certainly understand modifying the stats of the katana (perhaps even the length, such as making it shorter and faster) and placing it as a new weapon for these troops. I'm certainly not against it; I just had to toss in my two cents as far as historic weaponology is concerned.
Ah, and I'm eagerly waiting, of course!