Never mind the grapeshot. A catapault loaded with half-melted blue cheese would have the morale effects of hurling human carcases lol. "Oh man that stinks. I need to find a river to wash this ---- off. RETREAT!!" lol
OK, you've never actually met a real infantryman, let alone been near one in the field. I'm not an infantryman, I learned I'm a really good sailor and a quite bad infantryman (photo is of me in a Navy uniform...as a dirt sailor...long story). One of my problems with being a soldier is that I'm used to bathing at least every week or so and real soldiers go well over a month.
I do like the idea of civil improvements and developments having direct military benefits. Super-militarist civilizations should be routinely knocked over by civilizations that can field 10x the troops of the militarists and keep them well supplied in the field. What Lysander and the 300 did was force the Persians to hold in place and run out of fuel and fresh water. When you are talking stink, imagine hundreds of thousands of pre-industrial troops with dysentary because they couldn't boil their drinking water. That's the condition the Spartans imposed on the Persians at Thermapolae.
Is there any magic to provide field hygene?
(Yes, I know that the Spartans were militarists, but the Greeks/Pelopenisians as a whole weren't.)