If I remember correctly, the A-10 thing was discussed back in the late 80's right before the airplane was going to be decommissioned. They were also working on a version of the F-16 called the A-16 with a bigger gun and some wing mods. They brought some stock (camo green) Vipers to Ft. Hood to work the ranges there with the Apaches in an effort to see how the two could work together in an Army environment.
I think the AF bitched that that type of mission was the responsibility of the AF and not the Army.
Edited: Just found this. I was not sure if my memory was that good anymore. I guess I am doing ok.
http://www.f-16.net/f-16_versions_article18.html