I think the main purpose of HERF guns is for countering small drones in CQ. A major concern was smaller drones are able to basically sneak up to you, especially in urban environments. Initially it was expected to just shoot them down. However someone pointed out its not easy shooting down a nippy floating object the size of a football; people might end up missing and shooting each other
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As for EMPs, they've left speculation and are no longer restricted to detonating a nuke high up in the atmosphere. Initially it was hoped they'd be a good alternative to nukes for obvious reasons, but recently it was speculated that a powerful EMP would kill a lot of people too. Believe they can stop your heart.