Martinov, tested the scenario through again on expert/+2, this time as the Allies. It played very well, and was evenly balanced for a long time.
Germany cleaned up Poland and France very efficiently, and took Denmark (but not Norway or Sweden). No Sealion was attempted, despite clear advantage in numbers and quality (but see note on bombers below). The subs withdrew into the North Sea (!) where they were destroyed. Italy joined as France fell.
One interesting thing about air power. The Axis had air fleet superiority until the very end of the war in June 44, when Germany and Italy surrendered on the same day. I was never able to catch up with their initial advantage, but the British bombers were great! They did a wonderful job on Antwerp and Brest, in effect preventing a Sealion even if the AI had wanted to do one. They were also excellent right through the invasion of Europe, being tough enough to stand up to Axis interceptions. It was fun to have units like this that I would never normally buy, but that now had a chance to show what they could do.
All in all it seems the scenario is well-balanced and has an even more historical feel to it than the original 39 campaign. Well done again.