This is coolbert:
From the John Hawks weblog we have this item that caught my attention right away:
"If, as Keegan hypothesizes, the ration was one pound of meat and two of bread (requiring two pounds of firewood) per man per day, an army of 30,000 ate out a location pretty quickly"
Sir John Keegan in this particular instance hypothesizing that an army of 30,000 men during the Black Powder era of warfare, on the march requiring sustenance on a daily basis a significant consideration for a military commander AND THIS ONLY FOR MANPOWER.
As for the feed and watering of horses that were integral to the movement of the baggage train, the cavalry, the horses needed to pull the artillery, that is an entire additional matter of even more consequence, as should be obvious. Military campaigns during the age of Black Powder were generally put on hold during the winter, troops going into quarters, horses not being able to forage for themselves.
NO consideration either given for drink. Armies of the period [Black Powder] as part of the contract with a soldier agreeing to generally provide so much beer [northern Europeans] or wine [southern Europeans] per day ALSO as part of the daily ration! NO beer or wine and you ran the risk of mutiny!
"lieutenants think tactics, generals thing logistics"
Water from wells, rivers and lakes often disease ridden, and of considerable danger to a soldier to drink from, that number of troops dying while on campaign often in magnitudes beyond what ever casualties were sustained in battle.
[water and feet historically have been the two biggest killers of soldiers and not battle! Either not having enough water to drink or consuming dirty and diseased water, and those troops having bad feet falling out on the march and being set upon by marauders!!]
Read this CIC article by Al Nofi from StrategyPage. Even while in quarter, that rather smallish [even for the time] army of William the Conqueror  the logistical requirements immense, the DISPOSAL OF DETRITUS, EXCREMENT OF MEN AND ANIMALS BOTH A MAJOR PROBLEM THE SOLUTION OF WHICH IS UNKNOWN TO THE HISTORIANS!