I would not combine the branches of the U.S. military - we don't need group think.

Placing a certains number of A-10 squadrons under U.S. Army command seems reasonable.

The USAF would be our primary transport, space, bomber and fighter service.

The USMC would downsize (this hurts!) to three active MEBs which are organized more like 3 Commando Brigade and the quality training of those U.S. Marines would be more like the Royal Marines. The 4th MEB would the reserve brigade (rein) with three infantry regiments instead of one in the active brigades. The USMC would get rid of its tanks and attach Army armor if needed. I have not decided if the USMC should retain its air assets. If it does then a MAG per active MEB is reasonable. With USMC helos aging, assigning an Army CAB with UH60, CH47, AH64 aircraft to the MAG (under USMC command) might be the way to go.

I have a lot of ideas and will get to the other services later.