See its like this.You don’t use cfm for optium power with a Holley carb,but its generally more that you need the cfm for poor performing engines.Its all about the burn,you need to realise that.Its not the afr,but rather the way that the cylinder burns the fuel that the carb puts in.The worse the efficiency of the burn,the more you have to use more cfm if the carby isn’t calibrated correctly.You will have to increase the cfm to obtain volumetric efficiency and then use the heat from the overlap period of the cam together with the opoorly calibrated carby so that the cylinders don’t detonate.If the exhaust is restrictive,then a poorly calibrated carb can work ok,you see this in many forms of motorsport.These engines make all their vaporisation in the compression stroke.This style of engine doenst make power with a well calibrated carb and high manifold vacuum.You have to treat these engines like individual runner designs.If an engine gets a very good burn then you can use 1.2 cfm to get 1 hp. As the efficiency of the burn drops you fall back to using 1.5-1.7 cfm per hp.
So you see there are many ways to run engines but there is only a few ways to have efficient ones.