At the moment as I see it, the Germans need to do three things to "win": Build subs early, take out Cairo and have a credible Barbarossa. Unfortunately it seems that they can really only do any two of the three, not all three.
If Germans don't build the subs then Britain gets a free hand and which is a disaster for the Germans. Cairo is important because it is a much cheaper way to get two victory points than taking any of the Russian victory point cities (i.e., Leningrad, Moscow, etc.). As for Barbarossa, we've seen too often that insufficient early Easern front troops are a leading cause of an early German Gotterdammerung.
Not going after Cairo is an option, but it's just so damn attractive... and such nice triggers too!
The only solution I can come up with at the moment is one of two possibilities: Rely on poor Allied play or take minimal casualties in France while getting at least one or two triggers. Unfortunately, history seems to indicate that German successes seem to derive more often from the first possibility than the second.
dd