I’m sorry but i still have yet to see a polar express that worked. Japan can be ignored. My shuck begins in LA, because of that at best around turn 4 or 5, when G is already about to be on the ropes, i have to redirect units to fighting Japan, but that is planned for anyway as the US in no longer needed to finish off Germany. Also, a skilled Japan player can ignore almost any and all US pacific action using just her starting fleet for enough turns to get the massive economic advantage with standard openings.
Lastly, the main contribution of the US in my typical KGF is bombers, figs, and armor into africa while threatening Rome and a double drop on france. The beauty of this is against a polar express the planes can come home for a round, if no polar express the armor helps hold Persia. My standard US1 buy is 2 bomb, 3 arm. US2 2-3 trannies, destroyers if needed, more bombers, figs and/or armor. I only transport enough inf to load the trannies once and leave 'em in algeria, all other inf i stack and leave in LA they are just too slow. But with the US dealing with Italy/Africa and threatening Rome along with the nice SBRs, UK/Russia push germany back very quickly and very easily.
The problem is with the way the NOs are setup it is better to pound on one power and deny them there NOs and get yours, as without all that pressure you cannot keep the axis from achieving an economic advantage. If i loose my 2nd pacific NO but gain france in exchange, it was worth it.
Look at this this way, even if Japan gets to 70 IPCs, if Russia is bringing in 40+ (both NOs), UK 30+ (i love france or even a russian balkan invasion), and US 50+ (france, again), and G is down to 1 NO minus finland/norway, and Italy down to 9 ipc, allies have economic advantage, and location advantage. Europe is worth more than the pacific and closer than the pacific. It is easier to defend trannies in the atlantic than the pacific. You actually have units that live past turn 2 in Europe. There are more places to attack in Europe. Etc, Etc, Etc. By the time polar express becomes possible logistically, it is too late my units are already in place.
The UK can get 8 land units into Europe on turn 2, the US can land in africa turn 2 in force if desired. What can the UK / US get into the pacific that quickly? A few boats that can’t even defeat Japan’s navy, or an IC for Japan to take.
It is what it is, there is no simple ‘tweak this area and the game is fixed’. Hence, I believe bids are the best way to do it, as with a bid I can decide what is needed, and where it is needed, in my opinion, to fix it, and so can you, each and every game. Maybe even cash only bids.