Criteria are basically "how easily I can win a campaign/reach a dominant position without relying on very tedious levels of cheese". Wasn't including LLs at all or faction-specific bonus mechanics (like ikit claw's broken workshop) for any faction, though I was including start position for factions which only have one start position or whose start positions are all easy or hard.
Dwarves: extremely good defensively, practically can't lose a major settlement if you build walls (can farm money by letting revolts spawn in fact and autoresolving them). Awful growth but their units unlock at lower tiers than others, level 2 is quarrelers (spammable shielded ranged units = good, sadly no AP like the god-tier darkshards), tier 3 is longbeards, irondrakes, and shielded handgunners. For all intents and purposes a tier 3 dwarven army should be able to beat basically anything. Armies have the ability to instantly recruit slayers in the field which is a decent ability to temporarily shore up a battered army. Lords are great, runesmith heroes are OK, Master Engineer heroes are excellent. Diplomacy is OK as an order race but all dwarven start positions are kind of just SHIT with you surrounded by factions likely to declare war on you, so lots of multi-front wars.
Ogres: Haven't played them in immortal empires. Camps are great, kind of like a stationary black ark that generates money. From what I can tell you can now get infinite amounts of them at the end of the tech tree which means theoretically infinite money and infinite amounts of defensive armies around the map. Maneaters are great, especially with pistols. Decent magic. Huge campaign movement range boosts. Some bad matchups (e.g. a high elven army composed entirely entirely of lothern sea guard with shields, spears, and long range bows would suck). But generally easy start positions and they are a bit unique in that everyone is kind of OK with them.
Kislev: All of their missile infantry are great and synergize well with ice magic slowing things down. If you look at their garrisons 100% of their units are ranged except for 1 cavalry, and its a great combination of guns and arrows and they also have decent melee stats to hold off enemies and avoid routing. Invocation of Ursun is also OP to keep up 100% of the time since it will forever cause attrition (fucks with AI), gives another ice ability, and when upgraded gives additional melee defense to everything which makes your ranged units actually tanky. All this combined makes them absurdly rock solid defensively, probably the best in the game. You can basically rush half the map with tier 1 kossars just relying on your excellent defense to cover your ass. Helps that you have decent diplomacy and start near a lot of imperials that won't attack you.
Empire: Literally just decent all around. Great ranged capability, good magic, decent heroes, outriders with grenade launchers and mortars can commonly win whole battles with 500+ kills. I have heard that the Elector Counts system was fucked hard by the warriors of chaos addition though. Have only played Volkmar in immortal empires and he's absolutely broken and boosts the faction to almost S-tier.
Honestly curious what you think a faction needs to be "good" if you think all of these are bad. None of them are even close to the pain that is playing something like Nurgle.
Dwarfs: Slow on the campaign map (Grombrindal helps with this), slow replenishment (Grombrindal helps with this as well), slow growth (especially because you have to choose between growth and income in minor settlements), the only units they can recruit without a building are miners. They have good early armies, but getting to them is a pain and very slow. On top of that, the grudge meter is busted unless they've fixed it by now, but I consider this a bug, so I'm not counting it as a legit con.
Ogres: You can only build up to 7 camps with the appropriate research (unless this was changed in the last patch?), two of which are at the end of the tree. That's definitely not enough for their objectives on the immortal empires map. They are ok on the RoC map, though.
Kislev: Hybrid units are jacks of all trades, master of none, especially the kossars, which are the only units you can rely on in the beginning. They are ok in melee and range, but they struggle against armored units. A lot of their provinces don't have major settlements. Their economy is not the greatest. Their starting positions are not ideal too, Katarin can potentially have up to 6 LLs around that hate her (realistically only 5, but potentially up to 6). She is arguably one of the hardest campaigns atm. Kislev doesn't struggle with growth at least, but they struggle with the starting position, devotion, the supporter system, the early game armies not having armor piercing, etc.
Empire: Their mechanics are outdated/outright broken and that's especially rough for Karl Franz, who has to deal with secessionists, Festus, Sylvania, Grom, but it affects 3 out of the 4 LLs. Their mid-game army is very good, but getting there is a pain, just like with the dwarfs. Their AI allies are terrible too.
Like I said, you can *eventually* do well with anyone, but that misses the forest for the trees.
