They're making these games for 13 years already and every single one of them is still horribly broken piece of shit.
For example HoI 3:
Why bother having reinforcements cost at all if it's 1% of the IC cost to build ( 5% of the unit IC/month build cost and it takes a single month to reinforce from close to 0, while average unit takes 5 months to build ).
Units regenerate their hardware for virtually free, so there is no point in building any other units then the most IC heavy ones ( Soviets are exception with their event, that artficially flood them with manpower ).
If you abuse IC heavy units and popamole reinforcements properly, you can paint the whole Europe map with a minor/medium power like Poland, or Italy all by yourself - ridiculous.
You can't fix reinforcements "regen" by editing text files because the game uses the same mechanics for mobilization and realistic cost would make it impossible to mobilize.
One of the patches hardcoded mobilization/reinforcement cost multiplier to draft politics making it further not feasible to mess with reinforcements cost.
Depending on the draft politics units can cost a tiny fraction of IC to build and regenerate to full strenght for free upon mobilization - WTF !?
Peacetime unit supply cost is a *percentage* of your total IC, so the ammount of units you can supply during peacetime is independent from your industry size - WTF !?
Etc. etc. The list of the retarded broken shit in all aspects of the ruleset is endless...
AI is non existant, it'll just wander randomly in the general direction of the enemy. It's not aware of the combat rules, terrain, wheather, etc. army composition for each country is statically scripted by year.
Who is enemy is determined by threat mechanics, which in turn is heavily influenced by scripted events, unless players interference turns situation ahistorical enough, to break scripted events chains.
I've wasted tons of time trying to fix the worst offenders by modding, but way too little stuff is externalised into editable files and you always stumble upon some hardcoded roadblock.
It's impossible to fix the core of a paradox game by modding, at best you can seriously rebalance it.
Either their designers are retards, or they don't shy away from mutilliating the design, when testers can't cope with some mechanic.
If you read their forums it's clear that their audience doesn't understand the rules, but the games can play decently by themselves and retards are overjoyed they can larp Stalin, or whatever.
From HoI4 dev diaries, for every issue from HoI3 fixed, I see signs of equally retarded brokeness in some other area. I have no doubts it will be as shit as any other of their games to date.
What was exciting about their concept, was having a platform for exploring plausible alternate histories, by which I mean histories that unfold in a plausible way, not repeating our history.
They fail at delivering that and if I treat it as pure abstract games with a historical paintover, than I see no point, since the classic 4x games are way more interesting and fun to play than Paradox stuff.
I've kept throwing money at them to support the idea which I loved, hoping that the next time they'll get it.
I've wasted 200 euros over these years and tons of hours and never had any fun with their shit. I feel cheated now and hate Paradox this much.