Since we have Army Pants, why not add a shirt option to complement them? Find them in Surplus stores and dead soldier groups, made of cotton, reinforceable, with low warmth and slight storage, not very different from a dress shirt, really.
Nothing groundbreaking, but a cool way to roleplay as a soldier with a full outfit and all. T shirts and tank tops don’t really ‘fit in’ with an official uniform.
I mentioned the pants/shirt issue to the staff at my FLMSS* the other day and basically the only thing special about army shirts is the camo dye job. Otherwise, yeah, they’re pretty similar to any buttondown shirt. Maybe 2 storage for the pockets, but nothing major.
(IIRC dress shirts are encumbrance 1, though, so you’d probably want some Tailoring if you’re a melee type.)
*Friendly Local Military Surplus Store