@all-encompassing-goose
The Axis (and Allies) made some major mistakes, so I think the Axis could have definitely won-China was a major factor in being a black hole for Soviet resources, and Axis Japan lost their capital the first time in the second or third round, a major loss in the Pacific, and the fact that when Shanghai was captured, the minor industrial complex would be destroyed. Even if Axis Japan got Shanghai back, that’s several turns of saving up before anything new comes out.
In regards to your house rules, I don’t think there should be an industrial complex in Portugal, in keeping with the rules of not allowing industrial complexes on 1 IPC territories. I especially like your IPC bribe of Spain. I just think 70 IPCs is far too big of a bribe-it still shouldn’t be too easy though, so to be more historical it should be 50 IPCs at most. Perhaps American and Soviet IPCs will only count half as much when it is still neutral. How would you track it though? Thank you! I also think that the starting amounts of infantry should be the same, and that they when they join either side, it should simply be that they are a pro Allies or pro Axis neutral, instead of being their own powers. Finally, only powers in Europe (not China or either Japan) should be allowed to give IPCs to Spain.
I think that if Spain joins the Allies, a dice should be rolled. A 1-3 Portugal joins the Axis, 4-5 Portugal stays neutral, whilst 6 has Portugal joins the Allies. This represents Portugal’s long alliance with the UK.