Gotta realize that Karnak has a serious hate on for anything with a white star on the side 
He does shy away from Anything American, prefers british - but everyone has their "interests". I used to argue 24/7 with his ideas, but its really just preference, he's been around long enough I respect his opinions.
I shy away from anything Late war and beg for early war/midwar because frankly these were planes that were the workhorse of the war.
Take the LaGG-3 for example, it sucks against everything the Germans threw at it, however it was at the frontlines until the LA-5 started taking over.
Its nothing special, ugly looking bird thats slow, but its all the more reason to have it.
Beaufighter for example, nothing special but it was one of the leading ground attack aircraft for British/Aussie, and its twin engined! YAY!
As for Korean Arena, look at the WW1 arena - its dead - Korean war arena will last 2 weeks then be empty, if anything add the Jets to AVA arena and let people fly "Korean Theater" for a week.