In my experience, KGF is not surefire in 1941 setup.
If you have a meticulous player for Japan and a player with a good strategy for Germany, The Allies focusing entirely on Germany Leaves Japan free to roll over Asia.
Fast forward to 1944/45 And the Allies circling in on Germany. Yes, Germany will likely fall, but if Japan has meticulously managed her troops up to this point, Russia will have fallen or be about to fall to hoards of Japanese tanks.
My experience is that in any 1941 game with strong players, something has to be done to slow down Japan before she becomes a juggernaught, and this take away from the KGF.
Of course, this is my opinion only and my group of players is 6 strong leading to a heavy bias due to the low sample number.