In a world I'm working on there is magic potions of all kinds.
However since using magic directly in war is illegal, and few wizards make courage potions. The only thing left for generals to use is stamina potions.
Once it is consumed the person can march or fight or do exerting activities for at least half a day without feeling tired. [This is to simplify the whole thing]
This only eliminates the feeling not the actual psychical effects or effort.
And, somehow, they still retain their pain sensitivity as before. So wounds hurt as much as they do without the potions.
The potions are widespread and cheap enough so that a general can stoke on them, sending people buying it from several stores, and use them for battles as a more or less another resource.
There is no cultural stigma around it, wizards don't really care much as those potions are useful for people. And is view generally as just a thing to help you.
So the question: what will that mean to warfare? Like would it change anything or not