I see 4 bombers on axis side, i would use them to transport infantry to the eastern front or bombard strategically the southern russion provinces, those with 2-3 PPs
with 4 bombers you could reduce the reinforcements of the SU by 4 infantry each round, invading the turkey would even allow you to do some landing operations in the caucasus in the following turn thus force the SU to put garrisions far behind the front,
so they automatically lose the PPs from the grim up to moscow,
use your luftwaffe fighters to shoot down the SU airforce, at moment your airforce is to far behind, you can station it right behind the front line in the mech phase which allows you to use it as addition backup on counterattacks
