Pretty much the problem with everything 60 odd years down the line. But consider this when you consider propaganda, the Nazi's were the 1st political party to really exploit the mass media. Hence individuals like Rudel and Wittman having such a mythology around them.
With myth comes exaggeration and not just little bits as is more common with allied troops. Figure if one party flunky adds a few kills then another adds a few it gets out of control pretty fast. And try to extract the truth can be nearly impossible.
He was good at his job, even if you cut the claims in half, particularly if you consider the aircraft he flew.
As for political views, there is no country who can throw the 1st stone. In that time frame the Nazi's and Stalin were the worst, you can debate who was the more evil. But the US, and the Brit Commonwealth were no angels either. Unless it is a huge factor in the individual makeup it is best left alone.