You might be able to fly some US fighters to India via sub-Sahara Africa to India. If Japan cannot get India until J5, they may get there in time to save India.
Also, on turn 2 maybe the French fighter can start flying to Moscow from Scotland, than maybe get to India in time to help defend it. Or have it fly on turn 1 to sub-Sahara Africa route.
This is not a winning solution but it might buy some time.
If you don’t want UK to scramble during your amphibious assault, you need some Italian Bombers to raid the Airfield, and now UK have no change to repair it before Germany attack.
The rules are made this gamey way because the designer love the idea of teamwork.
Just bought the two 1940 games, and I definitely recommend buying the boxed games. It’s just a whole different feeling; opening up the boxes, setting up the pieces, etc. Really makes you more immersed in it.
New Guinea is after Greenland the largest island in the world.
The fact that Japan can scramble is a big advantage, of course. But if it gets to that Japan is in serious trouble. Then you need to hold out until Germany captures Moscow and Italy captures India.