Great question. I'm glad you brought this up.
I'd definitely think that we need a US National Guard category, and also subcategories for the state units, e.g. a Georgia Army National Guard category that would then get categorized under National Guard, US Army (I think), and Georgia.
The question of granularity, though, is a tough one. Should we also have battalions, units, companies, etc?
Part of the question is how many profiles we expect to be categorizing. We don't want to set up thousands of empty categories, but we also don't want to spend a lot of time categorizing profiles when the categories will have to be changed later.
Changing categories isn't hard. You just need to change the tag in the profile. But you have to do it in every profile for the category.
I don't know if that's really an answer. I'll be interested to hear if others have thoughts.