I think I have a good suggestion about making AI perform a lot better in historical events mode, starting the game in 1936 (I have played Europe 1936 with exact or random hitorical events several times). AI does not take advantage of guaranteed peace and no barbarians for many turns in the begining of the game. It starts building military units in the undeveloped citys, when it is a better strategy, I believe, to improve your infrastucture by building workers and factories first. I think there should be a production queue for a game start, which AI could not change until it is completed. My suggested production queue would look like this: worker (from 0 to 2); vehicle, air and naval factories, barracs. There could be build 2 workers if a city can produce one in 4 turns or less. And there might not be a point to build any workers if a city can't build a single worker faster then 12 turns. Start building factories right away then. Barracs should be in a scripted queue becouse I am afraid that as soon as AI will get control of what to build, it will start building units without barracs, meaning without promotions. While with factories in place, improved land and population more then 4, barracs take only 1 or 2 turns to build.
And a second thing. Free workers, which start in a capital city in the begining of the game, should be spread to start in other cities. I worry about cities in Africa, which belong to France, Italy and UK. No workers start there and those cities mostly are to weak in production to build a worker fast. Workers have to be shiped from the Europe, which is too difficult for an AI, I am shure. Most often there won't be made land improvements around the cities in Africa, controled by AI. And those cities build only 2 or 3 infantry units till the begining of the war, when it is posible to get even more tanks from every city.
So my suggestion in short again is:
-Starting production queue of workers and factories, which AI can not change, until it is completed.
-Spread starting free workers.