Clay pigeon shooting expert
You make a good point but youre putting too much emphasis on the word majority so far as the smooth movement of a shotgun is concerned the weight ratio only needs to be 55:45% in favour of the leading leg.
Such a weight transfer will not impede gun swing but it will help ensure our head remains on the stock when a shot is fired. It also ensures the stock rests comfortably in the shoulder pocket and allows our upper body to ride and absorb recoil from the shot.
Of course nobody would want to put too much (or all of their) weight over the front foot because this would certainly impede the movement and mobility we need to deal with fast moving targets flying at all sorts of heights and angles.