There is no aerodynamic mystery here. The relative performance capabilities of two-bladed vs multi-bladed props was quickly established at the dawn of aviation, & the physics hasn't changed since. Two bladed props will always outperform multi-blade props, & single-blade props outperform 2-blade props (that's why the C/L speed planes use single-blade props). Valid uses for multi-blades on a model are chiely diametral constraints and scale appearance.

BTW, multi-blade props do not change the stall speed of an aircraft.