Actually the A-1 Skyraider was the platform it was derived from. . .and the P-47.
See #62 from a knowledgeable retired USAF FReeper who corrected my nomenclature error which I acknowledged @ #71.
The A10 was not derived from the P47 or A1
The P47 was designed in WW2 as a high altitude air superiority fighter.. that the reason it had a turbo supercharger... but is was found to excel in the ground support role..
A1 was a light attack dive bomber..fit the carrier force mission of small carrier born aircraft for attacking Sea and ground targets.
The A10 was from designed from the start as a ground force support ,heavily armored, tank buster.
The closest ww2 aircraft that I would compare it to original concept would be the Russian Sturmovik