Re: "resisting" a push part 2
You can find videos of pushout, or other exercises pushes by people trying their darnedest to push people over while standing with both feet parallel. Ark does his pinky throwing demo too with either the feet parallel or a very shallow stance. None the less, to make these things work, you can't rely on structure, nor can you push back. If you push back you fall over, if you lean, your opponent can let go and you fall forwards.
The challenge becomes, how do you get that power back into the other guy when exerting any power of your own makes you fail? I've laid out enough of the logic for the astute reader to figure out a couple of things which are required to do it properly.