Using leg drive in punch combination hows it done?

[OMGWTF]

If you are pushing off to start a punch you are pushing that punch. You need to shift your weight first- ahead of the hip rotation- to engage the side of your body opposite the punching hand.
This gets your weight turned through the punch so you hit harder. You minimize movement so you're faster. You are in position to throw the next punch and your balance is better.

thanks grey thats a great tip you gave me b4 and ive been working hard on it, but that doesn't answer this question, even with my weight on the opposite side I cant bend one leg and straighten the other fast enough to get leg power in all the punches in a combination. I can only get leg power in a single punch. As soon as its combinations I use mostly hips and weak assists from the legs.

Is it impossible to get optimal leg power in a combination of punches?