People all over Europe were shocked when they saw Napoleons army for the first time. The soldiers were often on the border of emaciation, they were small in girth and height. By the time Napoleon was crushing all the armies of the continent the french had already gone through many lean decades. Like the citizens of modern North Korea, famine had wasted the men of Napoleons army down to the nubs. Despite this the French dominated pretty much all who stood before them.

Superior strategy and to a lesser extent tactics more then made up for the French armies physical deficiencies. While I don't doubt that having physically powerful soldiers is a boon for any army, if you were to break down and quantify the factors that lead to victory I think physical strength would be way down the list.

Pretending that a lack physical stature and strength is a reason that Women shouldn't serve in combat roles is nothing more then a misogynistic smoke screen. Factors like good optometry services, comprehensive, marksmanship programs, and quality logistics and maintenance of equipment are much bigger factors in the effectiveness of a soldier on the modern gunpowder infantry battlefield then raw physical strength.