CFM only really comes into play at WOT.
Think about it. A "butterfly" or air regulation device controls the air fuel mixture delivered right up to the point it is perpendicular to the plane of the intake. The air/fuel mixture is relative to the throttle position, desired speed and flow of the engine. You are not flowing 750 CFM all the time. You flow what you want the engine to spin at by your foot.
However, if you WOT, you want the engine to jump to the fastest it will turn in the least amount of time. Hence the ability to deliver a Max CFM.
Just my opinion, I am completely nuts by several peoples standards, but I have a good time with it.
