From gauging many hundreds of props over the years, what I figure is if the mfg's have some kind of theory they base their pitch/progression/blade area/aspect ratio/tip shape/airfoil/thickness/flex/stiffness/and a few others on, many of them blow it by poor quality control. Having done some QC on the props I've bought, I really didn't see anything that led me to believe they had any way to design and produce props with anything close to a guaranteed pitch.

If you think about it, the power input to the prop would have an effect on the performance. They're telling you with their advertised pitch what performance you're going to get and they only have a rough idea what power you're going to have to apply, how big/heavy/slick your model is going to be and a few more.

Good thing is whether or not a prop "over produces" means almost nothing other than that prop mfg didn't brand that line of props with powerful, small frontal area, slick, light models in mind.