Here's a 75mm pack howitzer. I would love to see you hump this one
75mm pack howtizers garnered their 'Pack' designations by the idea that pack animals could carry the lightweight 2000 lb. system. (most common in World War One but not uncommon in World War Two for either side).
The system was designed to be easily taken apart in multiple pieces (the M1 carriage could be taken down to a total of six parts while the gun system could be taken down to nine parts, none over 200 lbs) for this very purpose.
A mule could carry 200 lbs. So can 2 grunts, if they really hump it. But it's become apparent you don't know much about grunts.