Battle Master is a fantasy world so exact details like height aren't necessarily true of the world.
A feudal infantry force might have considerably lighter equipment then a modern soldier. Many would have just a repurposed farm tool and the cloths on their back.
A unit equipped with hauberks, bucklers and a sword (which would be amazingly good equipment for peasant infantry) would be carrying about 40-50 pounds. The sword would be 1-5 lbs (A 6 foot long claymore could be as little as 5 lbs), the bukler probably 1lb, and the hauberk between 20 and 40 lbs. Compare that to the modern infantry gear of a kevlar vest, helmet, assault rifle and several magazines of ammo.
In any case flavor texts can simply say (rations are carried in your soldiers packs and on the backs of pack animals). The unit of one busshel per man still seems to be about the right standard.
