if your german players are attacking uk, buy all bombers with usa on the first round. This will make japan postpone his declaration of war (or 5 bombers fly into the united kingdom to defend it).
Trust me the 5 bombers make a huge difference in the battle for UK, because it is cannon fodder and sometimes you can get a hit with it (say germany gets 10 hits only and you lose AA guns and bombers, you still have all your other units rolling)
IF japan does not go to war on round 2, uk pacific and anzac will have all the dutch islands and make serious money to defend themselves with, so you won’t have to buy anything for pacific for awhile.
you may think the bombers to be somewhat useless in this scenario, but it bought you a round before japan blow up so think of it as free units, they can attack italians in africa, sometimes if you are feeling gutsy with russia fly in to defend russia when they are holding yugoslavia. you can fly fighters in off of carriers when russia then pushes to northern italy… after that you can take rome over with russia… (this is super funny and super GG for axis when it happens).
If your german players are always doing sea lion and united kingdom play, I highly recommend 6 artillery rest mechanized infantry for russia round 1, follow that with all mech round 2 with russia (+1 tank because you saved 1 ipc round 1 so you have 38 so all mech and a tank). You can make the push for rome, it is fun.
Round 2 with usa I suggest pulling a bunch of air from pacific to atlantic. drop 3 carriers and a destroyer. Blam you got an instant atlantic fleet. push that out and who cares if germany attacks it, you can afford to lose a bunch of naval and you can counter with bombers and your last round’s buy, you can fly that into italy with the russian push.
germany can’t defend northern italy and berlin. his option is to attack if he wants to save rome, usually usa / uk air with all that russian mech… makes a very bad day for germany if he attacks (depending on his casualties in taking london).
Be aggressive as allies. It is more fun.
There is a reason why people don’t actually follow through with sea lion now, especially when allies are crazy.