Baking up to the issue that started this discussion; these words from Lipps article get to the point.

You’ll notice I never once used the word “pitch” in reference to my propeller. In my opinion, that word should be reserved for use with screws and worm gears that travel a definite linear distance per revolution. It is really an inappropriate, nontechnical term for use with props and introduces the idea that all propellers of a certain diameter and pitch are alike. It’s as if chord and planform have no bearing on a propeller’s characteristics; but nothing could be further from the truth! Go buy the same diameter and pitch prop from three different prop makers and you’ll get three different performances. That is the source of much frustration for someone shopping for a prop for his plane. To properly characterize a prop, the prop maker should tell you the engine horsepower required to turn the prop at a given rpm, density altitude, and speed, as well as the efficiency under those conditions. I’d like to see you get that information from any of them!