Ha! Tau Food, I wish I had a prize, food perhaps. You are correct.
I haven't read discussions of why the framers chose to refine ‘Treason’. My guess is that “Treason against the United States has some differences from Treason against the crown.
Vattel has some interesting discussions about the Roman's disdain for taking advantage of an adversary based upon intelligence from a traitor, but nothing so simple as “aid and comfort” and the “two witnesses” requirement.
I got a chuckle out of that.
Now, why would a bunch of very loyal, patriotic subjects have developed an interest in a narrow, precise definition for treason?
Why was Clinton interested in a narrow, precise definition of sex? ;-)