But Dooku did have control over the droid army, and would presumably be in on the plan, which is basically to remake the galaxy to their liking, with strong leaders (them) in strong control. Once Palpatine declares himself Emperor and uses the clone army to conquer the Core, Dooku can do the same with other worlds, unmatched by any force of similar size.
This does of course take some preparation and organising, a whole cadre of subordinates who do roughly what they’re told for reward or loyalty or love of fascism, and many other things, but it’s a lot more straightforward as a plan than “have an unpredictable and chaotic war with a lot of moving parts for years, risking discovery and the Jedi cottoning on, trusting your ambitious and highly experienced and powerful apprentice, until you finally decide it’s over and declare yourself Emperor” which is what Sidious finally went with. It’s an idiotic plan, and only one a true drama llama could love.
