Although I do understand the frustration trying to match up planes based on speed charts, I have to say that's not the way we do things.
We use real in game checks to lay out the events. We spend a great deal of time putting planes in the conditions of the event, and seeing how they actually perform, and then balance accordingly. Oddly enough, we've ran BoB twice before, both sides have won very close fights, the plane balance is just fine. Far more goes into an event than matching the speed charts. Don't look to those as a major contributor to an event, you'll always be disappointed.
I think some people want balance but for me if its an historical event I want for some reason authenticity. It might be hard to get people to fly Heinkels and Dorniers if they are so vulnerable or 110's which I read in practice had to be defended often by 109,s.
Its what I am looking for but maybe it just doesnt make a good game
I would blance the superior planes with superior numbers on the inferior side but make the German planes fly over the uk which they did which meant more of them were always in transit especially the fighters. That is the game I want to play but I susspect that doesnt suit everyone.