Today, it would IMNVHO make some sense to have some fixed wing assets such as the A-10 under ARMY control, rather than that of the USAF. The USAF seems to harbor a secret strong bias against low, slow, ground-pounding aircraft. Sometimes it does strike one that their blue little hearts are really not 100% into CAS.
Was talking to a retired Army type some years back who mentioned that whenever possible in Viet Nam they would try to get Marine air support if it was available.
He stated that the Marine pilots would get lower and in general were more accurate than the Air Force CAS guys, though of course, there were some real hot AF pilots too but the Marines were more consistent in that type of job.