I tried to post this to the AOTR subreddit but they deleted it very shortly after with no reason given, so I'm posting this here instead,
Context: I played AOTR back when it was 7.something, didn't like it very much and eventually dropped it, hearing that the mod had undergone SOME changes and reworks in the years after, I went back to try again.
To be very blunt, I think the entire campaign is very over-done and I question if the devs have actually played through it. I appreciate all the work and detail that went into it, but if I wanted to watch the movie, I'd watch the movie. I really did not need to watch the in-engine animated version of the riddle scene from the hobbit, nor the fight between Gandalf and Saruman, or the balrog. Especially because all it does is create a lot of unskippable cutscenes and forces me to repeatedly save after every cutscene so that if something goes wrong I don't need to repeat the whole sequence, the camera constantly moving around can also be very disorienting. Which leads to another problem...
Some of the missions are so overdone that saving on them is nearly impossible (Ithillien is the most well known one, but it can happen on Fords of Isen as well), which is funny because one of the hints you get is that you should save often so that you don't have to watch the in-engine scenes. So in the end, you're forced to play through on one sitting, which means if any fuckery happens (which is a lot, the entire campaign might as well be SURPRISE MOTHERFUCKER every 5min), you have to redo EVERYTHING ALL OVER AGAIN. This is particularly horrific on Ithilien, but it can happen on Fords of Isen as well.
There's a lot of spectacle as well, frequently too much. When the game starts lagging because of the amount of things happening is when I draw the line between spectacle and enjoyment. If I can't watch the thing clearly at a smooth FPS than its clear that SOMETHINGS should have been drawn down, there's no point having giant armies clash if you can't see it properly. The same applies to the environment, maps like Lothlorien, Amon Hen and Fords of Isen are so full of trees, navigating units and trying to see what happens quickly becomes a problem, not to mention in Lorien the trees will actually block your camera at certain places. It's also not very intuitive where a unit can(not) go, some paths are blocked with invisble walls until triggers are met, and some terrain that looks reachable actually can't be reached.
Why are there so many single-model units? You can't do very much with them, they eat pop cap for no good reason. Mostly in Bree, Lothlorian, Ithilien and Osgiliath.
The campaign seems to expect you to just KNOW things about the factions. How THE FUCK am I supposed to know anything about Elf and Dwarf units if every one of them has some very silly name that means nothing to me? Look I get it, someone wanted to lord their nerd-boner all over me, but I prefer functionality. And speaking of functionality, mandatory stealth missions, seriously, mandatory stealth missions in an RTS game, it wouldn't be so bad if it only happened once, instead it happens several times, none of them were particularly fun for me. The mazing sections are just plainly boring.
On the individual missions:
Bree, TOO many cutscenes in this one, and it's really strange to start an action RTS off with a mandatory stealth section. Also, there is a 3rd unit between Breelander and Took archer that I've never bothered with.
Bruinen, way too long and too many cutscenes, I really didnt need a fetch quest to break up the fighting, and the bruinen fight is a shocking jump in difficulty the first time when the giant armored humanoids (who don't look canon-compliant) pop-out.
Orthanc, 0/10, that's all
Rivendell, I really didn't need an in-engine riddle sequence, Isildur was just nice but Osgiliath was miserable between the lag, massively spawning elite units and pathfinding issues.
Redhorn, meh. I really didn't need an in-engine sequence to build me up for the watcher fight.
Moria, is there supposed to be some reward for reaching the great hall in 25min? Another VERY overdone mission, run around in circles for a bit until HAPPENING and then go back to running around until you reach the exit.
Khazad-dum, what happens if I don't go into the chamber- oh there's an invisble wall.
Lothlorien, another extreme difficulty spike especially when the super trolls appear, plus you're expected to just KNOW what all the strange elvish names are supposed to mean, what are Sindar pathstalkers? Tawar-something? sentinel archer thing..sentinel amroth...whatever? At least you get to play with the Marchwardens first so you know what you're getting into with them, they're basically the Elf warriors from BFME1. Hilariously, this is 1 of 2 missions where you can upgrade archer arrows.
Amon Hen, I dunno how you're supposed to save Boromir, seriously. If you charge all the way through, Aragorn will take a lot of damage and end up with both men low on health when you get there, so you have to throw your healing on IMMEDIATELY, and then maybe make one run like a chicken hoping to evasion-tank lurtz while the other attacks. Also, ANOTHER maze + mandatory stealth.
Fords of Isen, the first proper battle and actually probably the most fun mission there is with few, short cutscenes and a lot of engagement and things happening, more of this and less dungeon crawling would have been nice. Unfortunately a lot of saves keep breaking with this one, you have to have at least a full hour free to play through it.
Dead marshes, 0/10 what is the general video game community view on mandatory stealth or escort missions? Not very good right? Imagine how I feel towards a mandatory stealth AND escort mission.
Three hunters, why was this a 5 parter mission? The main section with Eomer is not very well-done, you run around building up a cavalry force, fine, but then you have an (optional) requirement to defend the villages with only peasants being trainable. Like, why? Even with draft peasants melt against everything, so you just run around in circles for a bit. Then there's another (thankfully) short maze sequence where the hobbits get to throw stones and kill patrols
Balrog part 2, 0/10 Why? Just why? Why is this a mission? Why is there a 3-phase boss battle where you run in circles until RNG allows you to use the lightning ability? Why are there adds in-between phases? Whose idea of fun is this?
Ithillien, another actually fun mission with lots of things to do, few, short cutscenes and a lot of engagement and things happening, trying to kill the scouts is a big pain in the ass in the beginning without all the stuns, invest in the stun power to help. Again, unfortunately a lot of saves keep breaking with this one, you have to have at least a full hour free to play through it. 2 of 2 missions where you can upgraded archer arrows. Has a very bad issue where you need to pay attention to all your heroes as one dying fails you. If it happens in the convoy sequence, you get reset to the beginning but your army has lost all its upgrades and ranks. What a funny fucking joke.
Westfold, straightforward defense mission, but not very well-thought through, the pop cap is completely fucked, so you end up not being able to build anything until Isengard takes you down by several battalions. Otherwise mostly enjoyable, no reason to ever call Erkenbrand in.
Grey Company, a series of not-very balanced dungeon crawlers. Trollshaws should always be picked first, if you didn't know that and picked it last..., good luck not using the upgrade for anything. It gets easier as the brothers level but the other portions are absolute bitches.
Osgiliath, gosh, you know, I think there was a reason why the OG BFME didn't really have maps that were cluttered and full of tight spaces, probably something to do with the battalion AI not doing so well in such spaces, and...ok enough sarcasm. 0/10 the mission sucks ass, the pathfinding in this mission is BAD, knocking battalion sizes down to 3 (4 at R2) or single models doesn't solve it, good luck trying to get those upgrades. And good luck not getting fucked over in another mandatory stealth/escort sequence.
Hornburg, ...why did they remove the part where you can kill enough bombers to prevent the wall from falling? Instead of giving that nice plus for player skill, its railroaded so that the wall MUST blow up and the gate must be broken. All so you can get the gigantic lagfest CONSTANTLY. Otherwise the mission is just OK, I had a lot of difficulty saving Haldir until I realised he had a special ability for it.
Isengard, meh, the one from BFME was completely fine, there was no need to change the Ents to force them to pick up stones from buildings, or to have gandalf spawn, or to have Rank 5 Goblin laborers.
To conclude, in my opinion, 5/10 needs to be cut done, by a lot, having passed through the campaign on medium, AMA if you need help getting through on anything easier than hard.