How is Little Dragon Lady's left-right combat a kung fu?

Hello!

In Jin Yong's novels, Left-Right Mutual Combat is a very strong kung fu, which was originally created by Zhou Botong. Its magic is that it seems to be able to make a person divided into two, two against one, since it is a great advantage. In the eyes of many netizens, the left-right mutual combat is an indispensable factor for Guo Jing and the Old Boy to be strong in martial arts.

But the left and right combat is nothing more than a heart and two hands to use different strokes. But people have two hands is two hands, it is not possible to make a left and right mutual combat have two hands out of thin air, and like the dragon eighteen palms, empty Mingquan such kung fu this is for a sound with two hands of people use, imagine using a hand with this should be two hands with the moves how can be used well? Let's say there is a move where one fist is swung out and the other hand is used to protect the chest (in reality, the moves are generally like this, one hand attacking and one hand defending, which is more in line with the human body's coordination, and is more scientific), but with Left-Right Fighting, which is done with only one hand, is the move swung out or defending the chest? Or is it a chest protector? If swung out, but the other hand is not used to protect the chest, instead of another move like a hook punch out, and then the chest portal is wide open, was a move results in a life, is not ridiculous?

Particularly Mr. Jin let Guo Jing two hands each can send out the moves in the Dragon Subduing eighteen palms, and also all powerful, not the slightest difference. If he knew that Guo Jing could make moves with one hand that he could only make with two, Xiao Feng would not know how he would feel.

Jin Yong book is probably only eclipsed is specifically for one hand with the moves, but unfortunately Yang is a one-armed.