If its the enemy I guess I can understand it, like a mystical powers arm race.
Maybe, we can find a plot AROUND cloning without ANY stormtroopers clones at all.
You know, the bad guy finds a way to clone people and he begin to clone some high members of the Republic to take control, step by step. The Jedi begin to suspect something. Everyone's getting paranoid. And that is the Clone War, a kind of cold war...