I know this has probably been answered a million times already on the forum, but I couldn't find it easily. I thought I might just as well ask you. If I use the AI at an Army Group level, as opposed to a Theater level, or Army as opposed to theater, will that mean that the different AI armies do not coordinate at all? Like if I give two different AI entities objectives that are fairly close to eachother, will they support eachother in any way? The way I plan on playing, at least at first, I won't be making the minor decisions, I'd like to only make the big ones. If that means I have to only use the theater AI, then I'll do that, but it'd be great if I could use it a bit more in depth. Though, from looking at this AAR, maybe it's not really necessary? It looks like you roughly got what you wanted simply by being careful about setting your objectives.
I was quite desorientated at my first (and so far only) go with Germany, though I suspect it will be much better (even at Theatre AI level!) when I've had a few years to organize my own forces, as opposed to being thrown into the thick of it.