Ancient, Medieval and Early Modern armies lost more men to disease than battle. To what degree did generals and other commanders prepare for this? Did they raise twice the amount of men they thought they needed, expecting half to be lost to disease?

by Seswatha

ColdTeapot

Could you provide some sources that it was actually a usual, ordinary, common thing to loose more to disease VS to battle, rather than just "something that happened from time to time", for all those 3 eras you mentioned? Because it sounds like a bold statement