mmmm The Army never had the A-10. There was talk when the Air Force first wanted to get rid of them but when congress seriously started considering it the Air Force decided to keep them to stop the Army from having fixed wing combat AC.
I seem to remember pictures of A-10s with US Army painted on them, and also a story about how the air force did not like the US Army having them. I might be wrong.
Actually, the Army recognized the extraordinary high cost of the logistics supporting/fielding a fixed-wing aircraft at forward deployed locations, like fields, highways, etc, as well as the high cost of fielding maintenance pieces-parts and maintainers, and the heavy cost and logistics demands associated with ammunition storage facilities.
Budgets are put together by each service. A huge issue like transferring a platform from one service to another would be resolved by the Sec Def with presidential agreement and then, only then, is the PB submission sent to the House and Senate.
Congress is where the HAC and SAC take whacks at the PB, as well as the SASC and HASC do their editing, then a conference committee between the House and Senate comes together and horse trading takes place-—all about money and capability and a huge issue like transferring a platform from one service to another would be resolved by the Sec Def with presidential agreement before it is sent to Congress.
Basically, something like a platform transfer would require significant agreement between the losing and gaining service, and then the services would have to be united as they try and convince the Sec Def this transfer should take place. IF the Sec Def is convinced, then he has to convince the president to support this action. IF he is convinced then the PB is sent to Congress.
Not a simple thing and most certainly not something “Congress” would kill unilaterally.
The Army has weight restrictions on aircraft, the A-10 surpasses those weight regulations.