Actually, I thought with the lackluster acting and poor screenplay, the story is one of the saving graces of the prequels. Some of the plotpoints could definitely have been refined, but overall it's one thing I really like about the PT, especially Palpatine's politcal manipulations. The Clones weren't really a cop-out so much as an explanation of why it's called the Clone War...

And for the record, the Republic isn't without military forces: Planets are free to create their own Militaries, but there was no offical "Grand Army" like the one created in AoTC, and one was needed to fight the seperatists.