That's kind of an oxymoron. If they are a legion then that implies they are well organized and follow the chain of command, but if they are chaos then they would never follow orders and just do what they want.
Now I don't know about Steven Harper, but for organized chaos to a policy of George .W. Bush it would mean Bush smart enough to form a working policy and I highly doubt that. The chaos Bush created was purely accidental, making it true chaos while the Chaos created by this legion is not true chaos.
Maybe but there is still a pattern and intent, so I'm not sure if it counts. With George Bush, it was all accident and seem to have no rhyme or reason. The man was like chaos incarnated or at least as close to true chaos as we as mere mortal can understand it.