There's nothing wrong with wiggle room or what-ifs but there's also nothing saying that a player even has to spend his PPs. I definitely disagree that units should be intentionally assigned to the wrong HQ just to give players something to spend their points on. Which is what AE has opted to do.
Divisions weren't earmarked for the Pacific when they were formed. The Army (for a division, Marshall's level or higher) decided what resources should be sent where on a continuous basis. The PP system, in part, represents you, the theater commander, using your influence with people like Marshall to get resources committed. Having to do so is quite historical. Expecting that units will flow to a secondary theater without any effort on the theater commander's part is not. US theater commanders had to ask for resources, and then had to deal with what got sent (which often bore only a passing resemblance to what they'd asked for, of course). The correspondence between Dugout Doug and Washington would be hilarious if it didn't want to make you cry.
The Allies regularly discussed what nations would commit resources and where they would be sent. These agreements changed over time as the situation changed. If the war had gone differently (and we can be sure it will in the game) then different allocations would have been made. Yes, even as early as mid-1942.
Now if you don't want to think about those parts of history that's your choice, but that doesn't make them ahistorical.