What formula are you using for Wing loading that has volume in it? squared not cubed!
However, I do agree volume or as I would suggest "airfoil thickness" does affect your max speed and landing speeds... sometimes significantly.

Dash7ATP : correct "math is math" is not always as it seams. Reynolds numbers in practical use, allow the aero engineers to convert readings captured in a wind tunnel on a scale model to be applied to a full size aircraft. They is it in various formulas as a conversion if you will. It is not Linear either. But in the end it allows them to accurately predict the t-off speeds, climb rates, cruise speeds, landing speeds, stall speeds....flying characteristics of the new design. As he said, root issue is because the molecules can not be scaled down.

Everything in aviation design is a trade-off of one performance factor over another.

Kent Walters (1/8th AF, SBD Dauntless fame) has published many articles over the years trying to explain the need for "Scale Speed" in judging. Good ref material.