The Old Guard is not a bunch of REMF weenies either. The first prerequisite to be a Guard is to be an active-duty infantryman. And this isn't just a few dozen men, it's 2 battalions of a few hundred men each plus the HHC.
When I was still in the infantry, a memo had went out looking for volunteers to join the Old Guard. The list of requirements was impressive. I was 6'0" at the time, and I think I wasn't tall enough...lol.
The Old Guard is the military unit tasked with protection of the Capital. The DC NG is pretty much tasked with traffic control. Two companies of the Old Guard would rout the entire DC NG.