I really enjoy mods that limit NPC ammo. One of my favorites also limits the ammo for settlers and you have to visit the settlement after a raid to replenish settler ammo. What would be cool, and sorry if this is already implemented, to be able to "donate" ammo, and have that automatically distribute to guards, settlers or both. Or just put the ammo in the settlement inventory and settlers will top off after a raid on their own. If you have an advanced industry producing ammo it could also be used for settlement ammo replenishment.