You have to respect the way that Russell manages to manipulate people into voting his way, and the great leverage he gets out of the hidden immunity idols. I agree that he is be best "villian" of all time.
That said, the people he manipulates are just plain idiots. Russell makes no secret of the fact that he's in this for himself and will lie to anyone and everyone to advance in the game. Only fools (like Jerry) would trust any "promise" he makes. It would have been Russell taking the walk instead of Rob if the tribe's average IQ were higher.
By choosing Russell over Rob, the "villians" have squandered their numbers advantage. Rob could have held the "villians" together. When the merge does come, the "villians" will now be a fragmented mess that the smaller "heros" group will work to their advantage. Russell will continue to survive by his wits, while the another fool will be voted out each week. Even if Russell makes it to the end again, the other person will certainly win again.
Makes my sentimental favorite (Colby) look like a better bet.