Can Butler and Walker beat Vitali?

Butler is horrible, I still have a hard time believing he dropped Vitali in sparring. Maybe he dropped him off at sparring. The fact that's even known at all makes him one of the most overrated heavyweights in recent memory. Walker's a tough read. He's struggled every time he's stepped it up (and the cats he stepped up against aren't even all that), but he also has the right style to outlast (and outstink) any given fringe contender. He's also naturally big enough to where other heavyweights can't push him around as easily as, say a Calvin Brock or Chris Byrd. I see guys like him and Tony Thompson hovering around top ten status, but unsure how much further they go beyond that. To answer the question - I'd probably give Walker a chance to beat Vitali, though for the moment I still question Travis' chin. I don't give Butler a chance over anyone with a pulse, including even a crippled Vitali.