I agree with my friend Frank.
In my opinion if you close the doors of your hand to make a flat leopard fist you are making a solid beam like structure ready to support compression strains, but this structure is prone to fail on the doors( knuckles, wrists) if you apply little momentum like when you hit with an angle or the target moves when you connect it.
In the other side if you make a romboidal structure (like in the picture) you can hit hard "soft" targets and in the case of apply momentum or even hit a "hard target" you can collapse your leopard to a clenched fist quickly. It like a sismical structure, solid but mobile.
http://www.choyleefut.de/graphics/cl...5_PauChoy2.jpg
http://www.choyleefut.de/pages/masterclass4.html
In my opinion, it's not a question of mine is correct, yours is wrongs, just different perspective of the same style.