My argument was because Anakin was a Jedi before. All the other Sith in the Rule of Two were potential Force users who had escaped the notice of the Jedi. Anakin on the other hand became a Jedi, and even though he was a Sith Lord for a while there was always that little bit inside of him that was Jedi.
Exactly. The Brotherhood of Darkness was on the losing end, hence Bane's chance to convince Kaan to use the thought bomb. There was no way the Brotherhood would have won.