We have discussed the relationship between Germany and Japan in relation to a J1.
J1 is almost by definition a term that means Japan is going all in on the Money Islands and taking Calcutta.
What if Japan goes with what most players would call the sub optimal plan, go all in on Navy with your focus on Hawaii, ANZAC and the Money islands and play a defensive plan on the main land. Yeah, that plan, the plan that Japan tried to pull off in the real war.
J1 with its focus on taking out the pacific fleet and the Phill.
J2 mop up the remaining loose USA islands. Set up for a J3 on Hawaii or Queensland from the Caroline islands.
Now you really put the USA in the pickle. Japan is going all in with navy and pacific island hoping and Germany is going all in on UK.
Which way does the USA go? They cant go both.
Looking at the board the USA almost has to go after Japan because all they need to do is take Hawaii and Sidney and the game is over.
So, if Japan does this type of opening move, it is going to be really hard to defend Sea Lion if Germany knows the USA is not going to stack SZ91 with a huge liberation fleet/army.