These theories reflect small engines used in light civil aircraft but they go all to hell when you address large radial engines with pressure density carburetors. The pilot or flight engineer will set the mixture, which in effect establishes the maximum flow rate through the carburetor. But the ultimate control of how much fuel reaches the engine is an aneroid device that senses air density much like an altimeter and another section of the carburetor that senses impact air much like a pitot tube and an airspeed indicator.
Gleaned from my memory bank and what I remember from my mechanics training back in 1949.
