Well, because I believe in modesty I wouldn't call myself an "expert" I guess, but rather an interested person. And yes, the Swallow is a real weapon, albeit an unsuccessful one... Sadly. It's very cool in appearance, though! Melee weapons happen to be my favorite. So, to answer your question, yes the Swallow has been sited in history, and is indeed a real weapon, it just works better in theory than in practice.
Also, on the subject of "wasted motion", cyclone COULD be described as such a wasted motion, if it is used on only one enemy, however if used on multiple, then all the movement is totally justified. BTW, I'm going to be practicing in a Kendo class soon, so wish me luck!