There are a myriad of incorrct assumptions in your argument, but I'll focus on one. Pilots flying multi-role aircraft have to train for those multiple roles. They have to remain proficient in multiple mission and skill sets, many of which do not overlap. Do you think multi-role F-16, F-15E, and B-1 pilots/WSOs get extra training resources (flying hours and sorties) over A-10 pilots, who only train for really one mission -- CAS? Newsflash…they don't.
It appears you think CAS is nothing more than finding targets in a targeting pod. It is not.