You raise many interesting points, and I’ll try to respond to two of them. First, can a Southern Pacific strategy work for Japan even without assigning thematically ridiculous IPC values to tiny island chains? I think so. I agree that it would be off-putting to play a game where, e.g., the Solomon Islands plus the Caroline Islands were treated as more economically valuable than France. There are limits to how much you can edit the map without breaking the suspension of disbelief and ruining the theme.
That said, I don’t think the 1942.2 map would take all that much tweaking. On the 1942.2 board, players will occasionally send a transport to take Australia even though it’s not worth much, and there’s little or nothing to use as an encore. If you valued Australia at 4 IPCs, New Zealand at 2 IPCs, the Solomons and Carolines at 1 IPC each, and Hawaii at 2 IPCs, that’s 10 IPCs right there. It’s not hard to find another 8 IPCs in South America: 2 IPCs in Chile/Peru/Bolivia, 2 IPCs in Argentina, 3 IPCs in Brazil, and 1 IPC in Colombia/Venezuela. All together you’ve got 18 IPCs, which I think is very respectable.
You could compare that total to a Western Pacific strategy (India, Persia, Burma, Italian East Africa, Egypt, Transjordan, Kazakh, Yunnan, and Szechuan add up to only 13 IPCs) or to a Northern Asia strategy (Soviet Far East, Buryatia, Sinkiang, etc. all the way west to Archangelsk, Vologda, and Novosibirsk is worth about 13 IPCs). Either strategy plus Moscow is still only 21 IPCs. So the Southern Pacific strategy doesn’t strike me as hopelessly inefficient from an economic point of view.
Second, is a Southern Pacific campaign inherently too slow to be fun? I’ll readily admit that it’s less direct; if you head off toward southern Argentina, you are obviously not heading for the global epicenter of military power. You can’t force a British surrender by crushing Buenos Aires; that’s just not how that works. On the other hand, if the Axis controlled the entire southern hemisphere, with a sphere of influence stretching from Tokyo through Singapore, Basra, Addis Ababa, Capetown, Buenos Aires, and Sydney, isn’t that a kind of win for the Axis? I understand there used to be an “economic win condition” for the Axis where they could win by controlling 100 IPCs or so worth of territory, and although the victory city mechanic has never been well-executed, there’s no reason why it couldn’t be improved to the point where people actually prefer using a victory city win condition.
I think the whole “race to the capital” mechanic is unrealistic and less-than-fun anyway; if you sack one capital without wrecking the empire it rules, the people who live in the capital will just relocate the capital and keep ruling their empire. You’ll get some bragging rights and a few million barrels of oil, but nobody surrenders an intact superpower just because you squeeze into their capital – look at Napoleon in Moscow, or Robert Ross in Washington, or for that matter the British in World War II, who laid down supplies and trained secret army units in Worcester to protect Parliament, the royal family, and the BBC, with plans to continue retreating to Liverpool and then Canada if necessary.
So, yeah, if Japan just blitzes straight for San Francisco, then that’s foolish and the Axis will lose. Similarly, if the designers allow you to drive tanks straight over the Himalayas with no movement penalty, and you pass up that opportunity, then that’s foolish, and you deserve to lose. But if the designers tweak the map so that the trackless Himalayan Mountains and barren Gobi Desert and frozen Siberian tundra are harder to cross than the balmy, oil-rich South Pacific ocean – and if the Axis seize that opportunity to invade South America – then I think you’d get a really interesting game, where the players had to make gut-wrenching choices about what resources to invest in what theaters.