The rule of 2 is forsaken. It was a bad idea to begin with, if the sith ever wanted to have a chance against a jedi ruled galaxy.You mean the dark side force users who aren't Sith because there are only two sith, so we have to circumvent that by creating dark jedi, Emperor's hands, dark side adepts, etc?
"Only two Sith there can be. Master and apprentice."
"Who are those other people then?"
"Posuers and wannabes they are. Inconsquential to the story they will be."
Its a rule long forgotten by the Legacy era.