HEY! Think of all the BILLION$$ we can save by closing all the MILITARY bases, gunnery ranges and training facilities: We can just have the military practice side-by-side with their civilian 'counterparts' and display military force over citizens on a weekly basis...
Well, I don’t think building one facility means they will never have need to train elsewhere for that kind of thing. Posse Comitatus doesn’t have anything to say on the matter of military training, only law enforcement, so it’s irrelevant.