With what effort you did to study this, I applaud you. However, this is Bionicle we’re talking about. Even their “regular” sized swords are more broad then a real life broad sword. The closest I’ve seen to what you are asking is a drawing (although I think someone has made a model) loosely fitting the Chinese broadsword pictured above.
A black blade like that from Tuma also seems to be a popular choice for MOC creators.