Man...Zonakin clears this list. I can't see 6-8 killing RotS Dooku in seconds.
To be clear, I've always thought of the "Zone" buff as Anakin using the dark side with a clear mind, as opposed to being controlled by his emotions as Vader. So Zone Anakin is basically just RotS Anakin with a big dark side powerup to all attributes, without any of the negatives he had as Vader (emotionally disturbed/80% power due to mecha-suit).
How much of a powerup? Definitely not enough to reach his full potential (twice as good as Palps), but enough to put up a great fight and possibly win against the likes of Yoda and RotS Sidious. That's enough, IMO, to clear this list (albeit with difficulty near the end).