https://www.youtube.com/watch?v=Hc3vSUVwoyY
You can only have 2 Sith: A master who has the power and the apprentice who craves it.
And as Palpatine explained to Maul, he had been replaced.
If a dark side force user gets too powerful, the Sith deal with them.
Clone Wars is canon with the movies and Rebels.
“And as Palpatine explained to Maul, he had been replaced.”
Not Maul. Dooku. https://www.youtube.com/watch?v=xBbGmkMGyok
http://starwars.wikia.com/wiki/Rule_of_Two
Rule of Two is for a specific time and situation. That was after their infighting had given the Jedi a massive victory. And even then the rule is for Sith Lords, presumably there’s some layers of Sith below that title that’s never really been explained. If the Jedi had a rule about there being only 2 Jedi Masters we’d know that doesn’t limit the Knights level, or any of the ones below it. Plus of course with quadrillions of beings in the galaxy how are they really going to know? Until some other Sith gets big enough for whoever is in the “allowed” 2 to notice they’re just out there. There could be thousands, millions, just keeping a low profile. Which was the real point of the Rule in the first place.