I think the "unnatural" type of motion might fit if this is a mentally-rigid-serious type guy, like he's planning and forming ideas about what fight will be like when he starts bringing out the fists, but then thinks of the pose he's suppose to assuma and quickly corrects his posture.
if he's more like a drab-serious type guy then it is not fitting at all.
I still dont see the need for leg movement...scratch that, knee bending if he's not transitioning towards a diferent pose in the final frame, if you are adding the knee bending for realism, dont, have him move his waist (like he is right now) but dont have the legs move only strictly what they have to, to adapt to that waist movement, that'll make it far more natural.
Now it's completly passable though, you could keep it and it wouldnt look silly at all, maybe even benefit the character if he's the mentally-rigid-serious type, it could be like a quirk he gets from being so stubborn about the way he has to move.
I agree with pawige though, widening the stance just a little bit would be the best solution, that was the problem with the old one anyway, it would've worked too if he was going towards a new stance but bending your knees all that way down just to go back to the same stance could only look silly.