Ouch, that sounds like a mess.
Is just the basic game with Cathay, Kislev, and Chaos Gods playable? Or have all the patches caused an issue for those as well now?
My guess is this is played on line, and so the patches have messed everything up. In the old days with computer games, a person could get the original game and thigns would be ok if future editions had patches that messed up the game in a bad way.
For the bugs, there are faction specific ones, and there are game-wide bugs. I checked the Community Bugfix mod's
Github page for what's been fix (and what's not), and here are some notable unfixed bugs:
Broken abilities/skills for Cathay & Lizardmen
Dwarf runes available to the wrong race
Straight up missing textures for the Empire
And broken allied recruitment (marked as "cannot be fixed" (by the modders))
Notably, the allied recruitment system was something they promoted hard, so it's quite hilarious really. As of 3 hours from this post, a user on the steam workshop page also claims the mod is broken for the current patch and crushes the game (see what I mean about game updates break mods? The more complex a mod is, the more likely it's to break). According to the Github page, there are 160 bugs the community have identified that are marked as "resolved", in which 39 were fixed by CA themselves. So without the mod, you are looking at having to deal with 120 bugs while playing the game.
Like I wrote before, Total War Warhammer III (I'd refer to the game as TWWIII as the community did) launched with Kislev, Cathay, Daemons of Chaos, Khorne, Tzeentch, Nurgle, Slaanesh (yes they split the factions and filled it with unit champions and obscure stuffs), and Ogre Kingdoms -- however, the OK is only available via either pre-order (which I did, in my moment of weakness) or purchasing the DLC individually. The OK is, however, considered to offer weak gameplay and there was an animation bug that prevents the Ogres to do their full damage in melee as well.
Before TWWIII offers two forms of offline play -- the Realm of Chaos campaign in which you can only play as the base game factions, or "Immortal Empire" campaign, which is basically a battle royale unconnected to the Realm of Chaos campaign, that allows you to play any of the currently availabe faction across the three games (provided you own their respected game/dlcs). Apparently they now have two other modes of campaigns exclusively focused on Cathay and Kislev, respectively.
When Shadow of Change happened, I stopped caring about the game as I was already somewhat disappointed with the Chorf DLC (content, mechanics, units, lore, etc), and at that time, apparently Bretonnia and Warriors of Chaos (but only as Belakor) were also available to every TWWIII owner for free. And you'd get everything Bretonnia has to offer, since they never got many units from the tabletop to begin with. Oh, also Sigvald is in WoC and not Slaanesh because he was originally sold alongside Archaon and Kholek Suneater. Wulfrik and Throgg are also available only in the Norsca faction -- with no access to Chaos Warriors. That whole thing was just a mess IMO.
One of the biggest gameplay complaints that I forgot to mention previously is how they implemented "singe-entity units", which are units with only one model. This are generally all Lords and Heroes, and most large monsters. The problem with it is that they didn't implement character imbeddings, and to compensate for how quickly a model with just 3x-5x the hit point of a 60 hit point infantry could survive getting shot at by 80 archers, they just multiplied their hit points by 1000 and their base weapon damage by the hundreds.
For example, the
Empire Captain vs the
Greatsword, the Captain has 3688 hit points vs the GS' 76/per, he has 250 base weapon damage and 125 AP damage vs GS' 10+25. Because how they are just one model, they are actually really hard to kill in melee because how few models can get to attack them, allowing their obsurdly high damage output to scythe done entire units. Also the characters can level up and take additional skills in the campaign, such as the FPA for the captain and general, further empowering them against anything that's not also SE or just focus AP missile damage (because AP in this game bypass all armor if hit). A monsterous SE is usually harder to kill, and a monsterous SE character a complete nightmare, such as Kholek -- except for Greasus, because Ogre attack animation sucks.
Speaking of characters, it's about time I talk about how each faction works in the campaign. You start by picking a "race" e.g. Empire, Dwarfs, Beastmen, etc., then, as of TWWIII, you pick a "Legendary Lord", who leads your faction -- so Karl Franz leads the Empire (or Reikland, they changed the faction named after TWWII IIRC), and as Balthalsar Gelt you play as the Gold Order. You Legendary Lord never dies -- they will be wounded and taken out of the campaign map for a few turns, but you will never lose them. You can recruit generic characters such as Generals to lead another army, and you can recruit captains and witch hunters to be embedded into your army as heroes (but never lead the army) or to act alone as agents to sabotage the enemy army/settlements (but they won't fight this way). You start during your turn by moving your armies on a campaign map, spending resources constructing new buildings in settlements you own or begin researches, and you end your turn for the AI-controlled factions to do their things.
Most factions can confederate with other factions of their own race. So as the Reikland, you can, under certain circumstances, confedrate with the other provinces/Gold Order/Volkmar's Crusade/Wulfhart's Hunters, which gives your all the faction's armies, characters and settlements -- as they are. If a faction is destroyed before you confederate, you lose their faction's unique characters/legendary lords. For example, Marius Leitdorf is a generic Empire General on the campaign map (who uses sword & shield, I might add), but as long as he leads Averland, he functions as a legendary lord until the faction is destroyed or you confederate the faction; Gelt will remain legendary even after you recruited him. But you can lose legendary lords/heroes as well -- like if Volkmar, who's all the way over on the Southlands, dies before you confederate him.
The community was quite split on the legendary lord issue, for one, most older TW players preferred if their army generals can die, and that they can kill enemy generals off for good. Right now, one can kill Malekith forever and he will return just because he's all the way in Nagground and it'd be very difficult to wipe out his faction. The legendary AI factions also tend to confederate when they are down to the last settlement so as not to be destroyed. As you can imagine, this frustrated many players who underwent such expeditions past Ulthuan just to stop the edgy elves from raiding their coasts.
Others, however, want to "pokemon" the legendary lords, to the point that the "Recruit Defeated Legendary Lords" mod is one of the most subscribed mods on the workshop -- understandable, of course -- that and the reset confederated lord skills mod, because the AI cannot build a character's skill worth a damn. CA was going into that direction, such as add mechanics for the Beastmen to unlock the other legendary lords even when they are "dead". I don't believe this divide is ever going to be resolved truly. So far, however, CA's been catering to the latter, as they have continously sold their DLCs on new legendary lords, and have drastically reduced the waited time for wounded legendary characters so players can just play only legendary lords.
Though one thing of pride I have was late last year CA posted an infographic about most played statistics for TWWIII, and Empire, despite not being a default playable race (none of the 4 legenardy lords are free) was the first, followed by Cathay and then I think DoC? Kislev was considered very difficult to play due to their campaign mechanics.
