It makes sense to me: after all, we already know both Dooku and Palpatine's regular and sith names, so if it was one of them or Maul who ordered the clones, they'd have been be using Dyas's name as a cover. This is a standard theory.
But it's more convincing that the real Sifo Dyas ordered the clones, which means he had to be in league with Palps, so it stands to reason that he was secretly Darth Plagueis. He died ten years ago, when his apprentice, Sidious, killed him. Which means he came up with the Clone War plan and Palps just bumped him off and carried it out.
It also neatly ties together the two mentioned but unseen characters.