I don’t have absolut strategy with Axe. I won my 4 games with Axe with different players and, therefore, different alliance strategy that I had to deal with.
Reading you, it seems Japan always attack early in your games. What I do with Japan is wait until a killing shot to attack… and if none occurs, then I attack Allies on J3, perhaps even J4 since Japan is before USA. But sure thing is, if USA reinforce Hawai on USA1, Japan completly destroy all navy there. A real Pearl Harbor occurs with a devastating 52/22 against a max possibly of 41/16 for USA (Combat value/hit point). z26 would most likely be clear in 2 waves…
As Japan, I also attack Russia on the very first turn, no matter what Russia does at R1.
Usually USA will avoid that sure lost battle. Therefore they just can’t go to Gibraltar before USA4… by that time, Gibraltar is well defended, either by Germany or Italy, depending on the game.
IF UK attacks Italy, then UK will also loose all navy… in that trade I find Italy winner.
That being said, I would enjoy testing my axis tactic, I invite you in a game. As I said, perhaps elsewhere, without playing at least 10 games, no one (including me) can state the game unbalanced. I played over 15 games of OOB Global40 (on boardgame, not here)before saying there’s absolutly noway that Axis can win, no matter waht. I challenge any game tester to state otherwise.