A few weird things I noticed with the AI. I was Germany, AI everyone else.
First, rear garrisons. I had a game where I intended to ignore Africa and even pretty much the Atlantic and go after Russia starting Fall 1940. But then lo and behold, Winter 1941 I find that Gibraltar has only 1 militia, while Egypt was stacked with militia and a couple of infantry. It really wasn't on my agenda in this game, but I took Gibraltar.
Similarly, by the end of 1942 the WA were in Morrocco in force, but left Britain practically empty. I had time to build a big transport fleet and in Spring 1943 I took both England (nothing there but planes) and Scotland (nothing but a bomber and a flak).
In both cases, asserting in North Africa seemed inappropriately emphasized over defense, especially of Britain.
In Russia, the AI did not seem to recognize that my long supply lines to the Caucasus were fragile. The AI was very passive, only occasionally sending militia forward to reclaim territories I abandoned, which basically just let me whittle down the Russians by taking a few militia every turn while my tanks moved further into the Russian rear destroying production capacity. Moscow fell Spring 1942.
Finally, the use of transports was bizarre. After taking Britain and reclaiming Morrocco, the WA kept randomly sending transports out into the Atlantic for no apparent reason other than for me to shoot them.
By the end game, after I turned off auto-victory and the end date, the AI seemed suicidal (actually, this is much like a human would have been at this point). Washington was abandoned, with the huge stack of US troops in SE USA. A few raids put an end to US production.
I point these out just in case it is helpful in evaluating some of the AI weaknesses.