For vertical climb rate... long low pitch.

For max level flight speed... short high pitch.

The full scale Cap (and a lot of others..) has a variable pitch prop, and for take-off or maneuvers needing to make use of power at low airspeed, the pilot changes the pitch to a low setting.

A high pitch prop at high rpm but low airspeed... the blades can stall just like you can induce a high speed stall of the main wing, and get a snap-roll. This condition increases prop noise considerably. It also causes a severe loss of useful pulling power. (the power goes to making air turbulence instead of thrust.)