Worst/Toughest Battles of EW4

In my opinions, Battle of Austerlitz and Battle of Three Empereors (the same battle but in different campaigns) are too difficult: if you don't have a general you must buy one

Austerlitz is Tutorial-level easy compared to the hell that's known as SNS.
As long as you have at least Sophia/Kusaitov and Dumouriez though, the two Austerlitzs should both be easier to beat (no guarantee for 5* without S/L though)

No general?
I usually get at least Dumouriez/Kusaitov (or their various replacements like Gazan and Raevsky), and if I'm lucky in UK 1798, Sophia as well, before going further than Marengo and Trafalgar.

You mean conquest instead of campaign?
I always prefer to be overprepared than underprepared, so that's why I try to have good gens as early as possible.

To answer this we have to define hard. I think hard divides into three categories:
1. Generally hard: these missions are hard to just complete and play. For me some of those(till now) are great sea warfare and revenge of the british in rise of USA and austroturkish war in hre campaign
2. Hard for 5-star: in those missions it might be easy to complete but you need to take your time and you can't just get that 5-star. For me some of those are russoturkish war(and it's two unlockable missions, no spoilers), war of glory in coalition(though i was so close:( ( and north america 2 of imperial eagle(of course there are more but too lazy here).
3. The annoying ones: in those you can beat but you see all the objectives and how little it begins you with which it discourages you. Also those missions usually have something that keeps you from winning them nice and easy while you juggle five bowling pins which you notice only when it is too late. Some of them for me are coalition disruption, battle of embabeh and reconstruction of the empire

Of course my info isn't complete mostly because i won the missions with the first try and i never played them again
And before you experts and nerds reply yes i know i could include a category with missions that are easy without generals and those impossible with a bazillion davouts but then the list wouldn't be objective enough because not everyone had the will or time or money or brain to get good generals and train them to max ranks like many of you do. This list was made for the middle player who plays both conquest and campaign(and less to answer the question:D).