Some years ago I first heard of the structural balance factor promoted by Charles Poliquin. I find it kinda weird that a coach would go by numbers to a that great extent, but anyways ...
In this blog post, Poliquin states that you cannot pull your shoulders too far back:
What do you think would happen if somebody did only pulling motions for years:
Would he be a powerhouse or would his progress stop sooner or later since he doesn't train his pressing muscles?