"Yoda>Sidious>=Dooku>>>B-team"
Perhaps in a pure "skill", Dooku could be nearly equal to Yoda and Sidious, possibly Sidious' true equal or marginally superior.
But it's only a technical skill. Ant's statement as accurate, even with all of his skill, that matters in single combat, even against stronger enemy, Dooku was far froim being equal to Yoda nad Sidious in raw-power, speed and stamina. Dooku, Mace are below Yoda or Sidious. Either of them has never shown a capability to overhelm three Jedi Council members level at once, like Sidious did in ROTS and Yoda did in Shadow Hunter against Tiin, Koon and... was it Billaba, as I remember?
One tier difference might enable you to compete with stronger rival. That's why Dooku and Mace were able to compete with Yoda or Sidious, and that's why Fisto, Tiin or Bulq were able to compete with Dooku or Mace, but couldn't with Palpatine and Yoda.