Darth Bane created the rule of two because he was opposed to the Sith Empire's views but ultimately because of the rule of two the Sith lost I mean look at it this way Sidious put too much faith in himself and Vader's loyalty and ultimately because he had only one apprentice there were no more Sith. I guess what I'm saying is that I feel The Sith Empire of the Old Republic was superior but only because of a quote by Luke Skywalker in the Book of the Sith. Bane was wrong. The force is fire. When the Emperor held power, the Jedi were nearly extinguished and the galaxy suffered. I have worked to restore the Jedi Order, and we grow stronger as we pass the flame our light spreads.- Luke What I'm trying to say is that since the Sith are limited by two that makes them more vulnerable. Granted Sidious was very conceded and narcissistic(something the Bane warns against in the Book) so perhaps Sidious was more to blame and not the Rule of Two.