Imo, Revan's version of the rule of two made a lot more sense. Two sith lords, one master one aprentice, and lots of cronies.
Revan predated Darth Bane by many, many years! Revan was to be the Emperor's Vanguard of the Sith invasion of Republic space. When he failed, Revan and Scourge gave the Emperor enough doubt to wait a few hundred years - bringing the story up to SWTOR timelines.
Darth Bane comes long after the time of SWTOR.