Having read the forums, but not played the game, I must note, it seems like HoI4 suffers from an AI that is even worse than HoI2 in some basic ways.
As far as I can tell, from the forums, the division designer basically has a best design, and not much else. The game doesn't really reflect why that design didn't work so well in history, and in the process turns the entire thing into a "noob and AI" trap. If there is one correct design, scrap the feature and just provide the unit!
It seems even in HoI4 they still haven't managed to resolve the fundamental naval problems that plague HoI2 once carriers are involved. At least HoI2s solution had a vague historical verisimilitude, once you skipped CVL+zerg fleets!
HoI2 isn't perfect, but in many ways, most of the problems with it could have been fixed by simply improving the AI, IMO. The only glaring non-AI problem was naval balance being completely ruined by the addition of the CVL, IMO. The base gameplay and scope worked pretty well. Major problems with the AI included:
- Not being able to handle naval range and logistics. AIUI this has basically been solved by simply designing the issue out in HoI4.
- Not being able to counter certain abusive player strategies, e.g. Germany going all in on u-boats, England going all in on strat bombers, etc. This, honestly, shouldn't be difficult to fix as the strategies tend to be telegraphed, and easily countered in 1938. (Start spamming convoys, escorts, destroyers for the U-boats, start spamming AA, interceptors, and Infra for the Strats) Either of these are obvious if you ever get any intelligence reports on the other sides build up. You are looking for them, aren't you?
Contrast with the issues in HoI4 (based on the forums):
- Division designer is a near trap. AI isn't very good at it.
- Naval combat has a "submarine minelayer" as a winning strategy, along with "Fleet in being" without scouting to avoid actually engaging an enemy to project naval control.
- Carrier effectiveness depending on which ocean you are fighting in, with the Pacific being worse than the Atlantic! Carriers as a 200 mile range gun seem almost sensible and sane!
- General obsession with fantasy alt-history. Honestly, from reading the stuff about the focuses, etc, I find myself wondering why WWII! If you change the players on the stage that dramatically, WWII wouldn't happen in any recognizable form.