The modern style boxing stance- I use that term loosely as I am referring back as far as the late 1890s, minimum- was developed to emphasize right hand power. In any activity that requires power from the right- hammering, throwing- the left footis forward, the right back. The reason you should keep your left hip/shoulder forward in your stance is to create a 'body swing' to generate pop inthe right. The force begins to gather at the floor as the wt comes onto the front leg then the right side of the body slams forward.
The thing about that stance is this; it not only allows for tremendous power fromthe right, with that full body twist, but now you can generate tremendous force with the weak or left hand. That is because at the end of the right the wt is on the left leg. By shifting it back to the right leg then swinging the left hip and shoulder to the right you can throw a hard left hook.The power is not in the left or right legs but in the transfer.
I know I'm going on and on about this but I'mjust not wording it right. Slam a door and kind of ponder the role of the hinged side. Then imagine that when throwing a right the left side of your body has hinges or it can be the right side if you throw a left hook. In either case your fist is the door knob.