I agree with Karl’s assessment. For the OOB set-up, Sea Lion seems like the only viable option.
Even then, the Allies might still have the advantage. But taking London early on (by G3) should give Germany a decent shot at the W.
If there is a winning strategy for OOB that doesn’t involve taking London early, then it would need a strong naval component, or the Allies will set up in France and USA will build a major in Norway.