Variations in Weight Displacement
When the stance is right for the individual height and body shape, maintaining balance is simple and repeatable. Maintaining a central balance point and good shooting posture so the gun fits is a result.
Women tend to have a top-heavier variance – some more that others – and men tend to have a heavy variance but lower around the waist. So it would not make sense for everyone to have the exact same foot position or weight displacement.
There are some things that must be pointed out. Whatever your shape, you will end up with more weight on your front foot (except for a high-driven shot in sporting) than your back foot. And the less that ratio shifts during the shot, the better you will shoot.
To be able to pivot around the front foot without shifting your balance point allows the muzzles to be moved more consistently on-line.
Conversely, the more your pivot point shifts from the front foot toward the back foot, the more likely the barrel will move in an arc – either up or down, depending on which way your balance must go to keep from falling.