I'm actually having some fun with this right now.
Even with the shit war mechanic?
I think the basics of the war mechanics aren't even bad.
You get a general (or many), you give that general an army, you set that army to attack or defend a front.
A front has progress bars for each faction and when that bar fills, a battle spawns (in which each side is either attacker or defender). The outcomes of those battles move the front (or not, if an attack failed).
The actual battles happen without your interference, based on military stats.
Supply is handled via convoys, which seems fine, but I haven't looked into that much.
This actually works pretty well, IMO.
The interface isn't the best, but if I could mostly figure it out what's going on in under 12 hours, it can't be THAT bad.
But there are obvious pieces missing.
If the game does not recognize something as a front, or not as a front "for you", you won't be able to send troops there (such as my issue above just unable to protect Lübeck because there's no front for me).
There are "strategic interests" and you can place them, but I have not seen any effect from this whatsoever, if there is one, it's not obvious.
Your tech seems to have extremely little effect on your soldiers' stats, which is awkward as hell - at least
there are mods to tackle that part.
There doesn't seem to be a way to tell the AI of your allies to do certain things. It hasn't been an issue for me yet, but I can imagine the AI can let you down big time.
Anyway, the biggest issue is not war itself, IMO.
It is the diplomatic plays, because of one big issue: War being pretty much the only outcome of diplomatic plays unless one side is
much stronger and the other just gives in to the demands.
The way it works is one nation demands of another "do this/give me this" and then other nations who have an interest (an actual gameplay thing, which I mostly like) can weigh in on that, declaring their support for either side and they can be swayed if you are influential, etc. This is actually a pretty good idea, I like it.
But the outcome is practically always war, even if one side (+ supporters) completely dominates. "Hey, Netherlands, I want this tiny piece of your colony cause its like right in the middle of my own. I have half of Europe on my side." "Nah, bro, I'm willing to kick off WW1 ahead of time for this useless speck of dust in Africa with one banana plantation. I really, really need that banana."
It works on the assumption that the only leverage anyone could possibly have is armies.
There is no middle ground. No negotiations, no offers or counter offers, no threats of embargos, no "I'll give you cheap bananas for X years for it", etc. It's all just "do this, or war".
The only real influence you have on it is who might or might not join a side in the fighting.
As one result of this, I barely use diplomatic plays. Yes, I could probably win the resulting war and it would probably be the best thing to do from an efficiency point of view. But going to war (or threatening to) for every little shitty thing is so silly I can't bring myself to do it.
As another result of this, AI nations are at war so much with each other, it doesn't seem to have any real impact on their relations.
Remember how US attacked and tried to invade me? Five years later, they are my best buddies with a trade pact. Both of which they initiated. I mean, I'll take it, but it's whack.