Only a person interested in air combat like most of us could find Polish biplanes or Chinese monoplanes attempting to put up a fight in the least interesting so I am assuming you want to see German aces or Russian aces and how they went about business. Question is what advertisers would pay for segments under that episode... probably the same ones that buy them now.
Not attempting to take away from your statement but I had to read it several times to understand what you meant. To be historically accurate, Poland did not use bi planes as fighters, only as recon. I have no information on Chinese fighters in WW2.
Yes, I would like to see some about Russian aces, but I would like to see more of German aces as some of these pilots flew the span of the entire war and I find their stories very captivating. When I searched last, I couldn't find an episode on the Battle of Britain which was very disappointing also. The fights over the channel, the initial match ups of BF 109's and the early spitfires, would be entertaining to most US flight enthusiasts as well I'm sure.