Russell is probably a bigger threat than Ronnie is b/c Russell lies and manipulates much more quietly and more sneaky than Ronnie does. Ronnie couldn't really control himself and was lying and just couldn't tone it down when he should have.
Russell not only got the outsiders to believe he hates Ronnie but he got Ronnie to believe he is still with him and he has influenced both Jessie and Ronnie while they were HOH's.
In many ways, Russell is a huge hypocrite and I felt like his actions toward Ronnie were unwarranted considering how he himself has been playing the game.