FAA's General Counsel has absolutely no authority over the US
Military.

We're talking about knowledge of the law.

The US Constitution, which puts the Military directly under the
President,

That's silly. Everyone working for the President doesn't have to obey
the law?

FAR 91.1 says that it "prescribes rules governing the operation of
aircraft...within the United States...."

Doesn't say "civil" or "military", so it applies to everyone, unless
the law itself provides the exemption.

Can you provide any supporting evidence at all to justify your
position?