AUDIENCE WARNING

What if the blast missed Fives and he escaped to fight another day. What if the word of Palpatine's betrayal got out and the sith lord was forced to give a different order, one that changed the course of the war. "Execute order 69..."
The idea is to kill the entire clone army in one sitting, leaving the Jedi defenseless and exposed by the sudden departure. Palpatine knows the Jedi's weakness is empathy and most will try to help the clones and now it should be easy to either drive the Jedi into hiding or have them killed. In just five minutes, the republic lost its entire army and is now exposed.