I think that the main problem was that Germany was a bit UP. +1% IC to admin genius and prince of terror, and +10% IC to Germany later, AI Germany has progressed to 2 provinces shy of both Leningrad and Moscow, making similar progress in the south (I'm playing my custom Chinese warlord; the unification of China is well underway and Japan has been off the mainland + Taiwan for 2+ years now). To be fair, it's still short of historical progress, and they did start Barbarossa in April, but if they keep it up next year, they'll break the Soviet Union, which, as Cpt. Obvious would put it, is "more than what they did historically". I have decisions for wars with both of them, but I'll wait for a clear-cut winner to make it interesting. Though I will have to conquer and puppet Siberia before I can get to Germany, if they win.
Edit: And as to why Germany was a bit UP? Well, it's by far the most played country - main aggressor = lots of activity, plus tank goodness and great tech overall, and since players have gotten so good at this game, Germany was the obvious target for (mostly indirect) nerfing.
Notice how, in DH, both the USA and the Soviet Union have huge advantages over Germany: The USA start with 500 base IC, which while historical, is still a f***'n lot (they have entered the war recently in my game and have 965 effective IC, this AFTER I slapped full Free Market countries, like the States, with -10% IC), and the Soviets have Stalin, who reduces the overall IC cost of units to 64% (65% for me as I've changed it to -35% unit production time), and European Russia, which can be attacked effectively less than half of every year because mud.
Edit: Never mind the States with 965 IC, they're full central planning because they put money in the CP-increasing decisions. They're down to a much saner level now: 728 (which would be 788 in vanilla).