We've been over this so many times, besides Akatsuki originally had ten members and the leader would never risk putting a Bijuu in one of his member when they go around getting killed and killing each other all the damn time. And you say being able to control a bijuu is a big if and I agree it is but I highly doubt they would be attempting to acquire all of them if they couldn't control them. Besides whats with that anyway, we've seen immortal guys, people coming back from the dead and all manner of nonsense and we know its possible for people to control Bijuu, like you said the 1st could do it, so why not an organization of super villains?