The Clones are well trained and based on Jengo Fett, so they have his physical attributes. The thousand systems may have wimpy militaries, but rely on the droid fighters to fight for them. If each clone can take out 10 droid fighters before getting Aced, then the number is much higher.

Don't those Clone Troopers look a lot like Storm Troopers? Hmmmmmmm, I wonder...