I'd say that this is exactly backwards. Certainly more so when it comes to Military pay scales.
Technically you are correct ~ but the top rate in the military payscale is "limited" (see reference above) to not exceed certain civilian senior executive pay levels, and that's probably why I was under the impression the limitation standard was based on what Congress critters get.
Anyway, no one gets everything the payscale says they can get ~ it's a trick ~ an incentive ~ to make a federal government employee think he can get a lot of money.