Ah, the age old question!
The answer is: Yes, the Axis have a clear advantage G40 OOB. No question. The reasons are clear and mostly stated above: Axis planes, victory conditions, weak allied economy etc…
Higher bids and balanced mod have done some good changing this, esp the BM.
However, how about this: forget the bid and BM and just change the turn order: Rus, Ger, Jap, UK, Anz, Fr, Italy, China, USA.
USA going last would totally F’ up the Axis, render almost all sea blockers meaningless, not to mention make the Berlin end run much more possible.