IMO, drop (elevation) and cast (windage) must be equal. It is a easy to miss a target to the side as it is to miss above or below. LOP is supposed to get the various body parts in alignment with the stars so they function harmoniously. Fit is to shotguns as sighting-in is to rifles and handguns. The objective is to have a stock that positions the involved body parts such that the gun can be shot more or less reflexively and expected to hit where it points. It should come as no surprise that one set of dimensions is unlikely to fit all guns for all shooting purposes over a shooter's life.
