I'm with Karnak on this one.
"fighter-bomber
n
(Military) a high-performance aircraft that combines the roles of fighter and bomber."
The Skyraider clearly fails in the performance/fighter part, not only against its contemporaries, but against fighter aircraft designed in the 1930s. The Skyraider was designed to meet USN requirements for a carrier dive/torpedo bomber. It does not possess the performance required to be used in a fighter role. It isn't in any conceivable way a fighter.
To say that the 190F is a pure fighter or interceptor and not a purpose-built ground attack aircraft is a mistaken belief. It is based on the 190A fighter, but extensively modified to carry out the role of bomber/CAS aircraft. However it retains much of its performance and potential as a fighter. Thus it is a fighter-bomber. The same can be said for many other fighter-bombers that started life as pure fighter designs, but with maturity and modifications became formidable ground attack aircraft as well. Typhoon, Thunderbolt and Corsair are obvious examples. The Mossie is an odd one that started life as an unarmed bomber, but because of its tremendous performance was modified to also be a fighter.