They change laws and such daily. Why not give them to the Army of Marines. Either would love to have them.
The Key West agreement forbid the Army from having fixed wing ground attack aircraft. Now in Vietnam we had the OV1 Mohawk with multiple pods of white phosphorus 2.75" air to ground "marking" rockets. There even may have been some with an M60 mounted on a "hard point". I have even heard of O-1 Bird Dogs with a M60 mounted in the rear compartment. The Air Force "defalcated a brick" when the Army mounted a machine gun on a helicopter.
The three services were there to hash out and define the responsibilities of each branch. The result was a "treaty" of sorts that became known as the
Key West Agreement. The is how the agreement broke things down: The Air Force would handle combat in the air and air transport but also promised to provide close-air support for the Army. As a side note in the early stages of Vietnam the Army was hauling more tonnage of cargo with the C-7 Caribou than the Air Force was. The solution to the "problem", all of the Caribous were transferred to the Air Force.