Nice Idea Leonid !
o American: P-47
o British: Typhoon
o German: Ju 87A/D/G or Fw 190F/G
o Italian: they had a light bomber, SR.79(?)
o Japanese: Betty(?)
o Russian: Il-2m/m3
A few alternate ideas though, and realize that I have a soft spot for two engined "heavy fighters" when it comes to ground attack planes:
American: P-47 is very good, can't come up with a better one, unless you go to the A-26 Invader or A-20 Havoc.
British: Typhoon again very good, but how about the Beaufighter?
German: Prefer the 190F of the two, the Stuka is not very survivable even in early war situations. Again like the British, however I would go with a two engine aircraft, the Me-410 Hornisse. Fast, tough, lots of different cannons to choose from, and able to carry bombs internally.
Italian: Here I will admit my total ignorance of any Italian ground attack aircraft.
Japanese: Betty may be very good choice, not really sure. Wasn't there a also a Ki-45 Nick? The "Dragon", that was twin engined and heavily gunned and bombed, that was optimal for this role. Admittedly, my knowledge of Japanese Air to Ground aircraft and knowledge is pretty thin.
Russian: The Sturmie or the flying tank!! Nice. An alternative would be the Pe-2 wouldn't it? I was under the impression that it was heavily used in ground attack missions, produced in incredible numbers, and much more survivable than the venerable Sturmie.
Just a few thoughts off the top of my head.
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