After playing some high-difficulty games some things become obvious which are real major issues.
Let's start with the general things that cover all civs.
first and foremost:
The AI doesn't aim to win. At all (even on Deity it has plenty of resources but no aim to wrap the game up whatsoever.).
And it really should. Since there are quite different options which should cover most situations it should also be possible to find something for every civ and most situations.
Thats the first thing you should focus your attention on. Its the one thing that should most seriously enhance the AIs ability to compete.
If it will try that in some way other than on accident players really will need to tone down the difficulty at least a bit.
To fix this lets have a look at the conditions available:
Altar: All Civs which use alot of Priests or Desciples and are good or neutral should definately try for the Altar of the Lunator. And hard. It yields really powerful benefits in Economy as well as the possibility to win (And even if AI doesn't suceed in building all even getting to step 3 or 5 will yield some serious economic + Military benefits. So nothing wrong for the AI if it tries in Vain.).
Civs that instantly spring to mind fastly in that regard are:
Malakim (what a surprise...), Elhoim (another really odd one, no?), Khazad (get some milage out of priests as wel), Kuoritates (due to being a powerful builder and being able to use the Benefits more tangiably due to fewer cities), Sheim (if they oddly turn neutral or good during the game. Especially if lead by Os-Gabella. If they later turn veil its still very good allowing to build Savants upgrading to Mages very fast among other things.), Embers under Jonas if they turn good or neutral, for Ljasalfar it might be ok as well, especially under Arendel. Mercurians also should have some serious incentive to go that route since they really have some leaning gamewise if not flavorwise.
Also its the best Condition to try for smaller empires where the other options are out of reach.
This is also a victory condition which is very viable / suitable to rather peaceful, trade-happy, tech-focused empires.
Sidar (because Shades are much easier to get in a city with the altar which is a real boon to them. Since Priests also Level on their own. Perhaps also fits them not so badly flavorwise) / other industrious civs could be made to try it as well due to being able to get the final one way cheaper.
Also the Cities with a higher level altar should be more prone to producing desciple Units than others (and at least the State Religion as well as perhaps others should really be spread there) since that makes the desciples built there potentially very powerful. (Like abovementioned Instantmages from Savants.)
Grigori even if not very "spiritually inclined" and without much benefits from the respective techs should seriously get their Lunator beeing able to construct the altar back in some way or the other (and they don't get much from those techs so some edge on that victory might seem fair) and go for that victory after SoW is researched. (Unlike the others they should aim for that one rather late though.).
And its the single most fitting civ going for that victory flavorwise. Its the ultimate in human empowerment after all. Even if going a bit farther than cassiel might have hoped...
Interesting Civics here are: Theocracy (and to a much lesser extent republic or God-King depending on size of Empire) / Pacifism / Arete, Slavery or Caste System / Agriculture or Guardian of Nature / Public Healers / Overcouncil
Religious: Every Civ that has founded a Religion early + built a shrine (which it should build more reliably) and converted some civs / allready has some considerable religious influence should seriously try for that victory. And fast. Time is a big factor here.
Thanks to inquisition (which the AI also needs to start to use if running a focused relgious game) this one should be quite achievable (especially if one big block forms). This is especially true for civs with a religious leaning. Looking above for the list of altar-lovers might give an insight.
Unlike going for altar this should rather be pursued by larger empires though. (Those should use Theocrathy and try to impose (by means of force if necessary) their religion as well as the civic on as many civs as possible and use Desciples quite liberaly. Also Purge the Unfaithful might be good for them.) (Followers of the founder should perhaps accept their founder going for that victory. Since flavorwise it is a Victory for them as well more or less. Perhaps big religious blocks vieing for religious dominance might be intersting)
Members of the Undercouncil might try this one perhaps since open borders can be enforced and CoE is spread rather easiely and hard to resist. Those Civs which are CoE and try for this one should also unlike others use the Spread liberally. Yields a lot of Gold from the shrine as well.)
Interesting Civics here are Theocracy (what a surprise...) / Nationhood , Social Order, Consuption or Crusade / Aprenticeship, Slavery, Caste System or Guilds / Conquest, Mercantilism or foreign Trade / fitting Compassion / Undercouncil.
ToM:
At least all Arcane Civs should try on this one if they at least own 4 Nodes. (A routine for building the towers and dispelling the mana might be hard to teach but it still sounds at least possible.) after Researching Arcane Lore / SoW.
So Sheaim, Amurites, Balspheraps, Svartalfar are obvious here. The towers are good in their own right and more
That could be done in conjunction with teaching the AI how to use magic properly. Others might fit as well.
Amurites should try this one from 3 Nodes ownership upwards since they start with Metamagic. Also they should start for it as soon as they get the magical-spheres/aspects-techs not just later since they get way most milage from the towers. And that should be their prefered victory since they have it easiest to do and also beeline that path anyways allready (at high difficulties they should be able to build all 4 aspect-towers before even reaching sorcery. Let alone SoW. That whould set some serious pressure on the player / other AI to stop them from winning by arcane might.).
Sidar could try it as well due to being industrious and having some advantage from different Mana (even though that one is far less interesting than the Altar victory for them.).
Grigori could also try that one if its a bit later in the game and much nodes are available.
All civs owning 6+ Nodes should perhaps try this one. Since its classic Builder, and the AI can rather easiely grasp how to build, it seems. Exept Khazad and perhaps some more simple Civs naturally...
Interesting Civics here are: God King (for smaller empires) or Republic / any fitting cultural / Slavery, Serfdom or Guilds/ any fitting econ/any fitting compassion/Undercouncil (for Slave Trade + free sience and immunity to tech-bullying.)/
Cultural:
All Civs leaning towards Culture / Bards / Recon could and perhaps should try this if resources are available and some Wonders or other Factors run nicely.
Balspheraph, Sidar, Svartalfar, Kuoritates should be quite suited for that one.
Favored Civics then should then be Religion or Liberty / Republic / Caste System / Foreign Trade or GoN or Agriculture / Public Healers or StW. Need not be to hard but are definately helpful.
Hall of Kings, Grand Menagerie (if possible in any way) and Theatre of Dreams sure help achieving that victory. As does having many religions and there temples in the cities. (Civs aiming for that victory should try to amass many religions. and focus their attention on some core cities.)
Also Civs in the Overcouncil might start to try on this one once Liberty is imposed councilwide.
Especially if done rather early.
Grigori might try as well in abscence of the possibility to win religious. (another one among the many reasons to give Honor / Deception and access to the councils back to the Grigori. Without overcouncil Cultural is so much harder.)
Due to the whole setup of the Civ and playwise this one should be one of the prominent Aims of the Kuoritates. Big Cities which are concentrated on surely helps achieving that victory.
Members of Overcouncil should perhaps also accept someone reaching cultural since it fits their flavor and is most likely to go that way.
Putting up the Culture-Slider and building Culture-Boosting Buildings might help to get there.
Domination: Civs that can easiely support huge empires and are powerful enough should try this.
This should include all followers of the Order as well as Veil and to lesser extent might be FoL, The Bannor and other Military Heavy Civs at least. Or anyone powerful enough to be reallistically able to round this one up. Other Civs might come to mind.
Civics which are interesting here are: City States (in times of peace) or Republic (otherwise) / Any fitting cultural which yields most happy/ any labor thats fitting the circumstance / agriculture or GoN (for pop) / Stw or public healers (depending on alignment) / most fitting Council but should lean to council and try to lead one.
Dominators should go for Wars rather late when blocks are formed (and the situation is clear) and Expansion is harder to do peacefully (they should expand "peacefully" very agressively / expansionist though.). But shouldnt restraint from taking something from a weak target if the opportunity araises.
Wars by dominators should aim for capitulation first and foremost and should aim at taking cities as oposed to razing them as well as be lead rationally and ended if its convenient. Partial Gains are fine if they offer a good deal.
Conquest: All the Civs that are more Militarily inclined (as represented by modifications to War-Weariness) could try this one if one of the other victories is out of the question. So clearly infernal+ Sheaim but also Calabim, Embers, Doviello, Bannor, Malakim, Khazad, Hippus and Mercurians might try for that especially one if nothing else is available. Should be prone to raze (depending on alignment) as oposed to domiation which should capture.
Obvious Civics are: Despotism or Theocracy, perhaps Republic / Nationhood, Social Order or Crusade / Aprenticeship or Military State / Conquest (could really feature reduced War-Weariness btw.) / StW, Fend for themselves or no care / Undercouncil or better no Membership to not be restrained by a council. (That should only be a rough guidline though.)
Oh and Warfare. Lots of Warfare...
The more fighting and the bigger, the better. World war is all fine if you want to take the world by conquest.
Conquerers should use force as the main way to expand if any opportunity araises and should war early and decisively. Elimination of Rivials should be priority. (Capitulation should be accepted though if potential Vassal is beaten weak enough. Elimination might be an option as well naturally. Especially for harder to controll civs.)
Razing should be the preference and resetteling burnt territory the better way to expand (unless the prize is very interesting like a big city / wonders or a really good spot). But War weariness and revolts just slow down in question. The War machine should be kept going and support down / advance up.
Important thing to note: Concerers should really dig diplomacy. Simply fighting everyone at once doesn't make one the only civ on erebus that lightly. Even Hyborem knows that.
So one at a time or at least managable wars. And Friendly / pleased ones should rather be last targets. Trading can help in warfare.
Oh and for the sake of the dominators and conquerers make War-Weariness less severe in some way (perhaps tied to the Armageddon-counter). And really go away faster. Its really a game stopper for all but the most extreme militarists. Only real peace-lovers should feel some sort of pain later on. FFH2 seems more combat focused in flavor and feature. This will help Players and Ai and perhaps makes waging war more fun. Im confident you may again find a way to even make an unfun feature a fun one via some tweak of mechanics. You have a real history for that.
Lastly Time: Civs that can't get one of the others or see other civs racing towards one of the other victories fast should aim for that one or at least try to prevent others from winning if its ok from the flavor side. (like everyone declaring on builder of ToM and evils on builders of the altar. Expanded on the other conditions if appropriate). Alliances should form under fitting circumstances against the whould be-winner.
Clear and major score leaders are perhaps the ones who should try for that kind delays actively especially if no other victory is near but the time-limit is. They should also try to dominate one of the councils and give resolutions which bind others civs attention like Councilwide-Proxy-Wars and the like. Also they should naturally try to inflate their score in any way possible. Especially if the end of history is near.
If this is possible in any way AI should recognize if a condition is disabled and don't try that route if its not possible. No point in building the Tom and inciting world-anger on you without any gain after all. The Altar is the exeption since the last step is really grand. So going for that one still makes sense
More later. Other very serious issues are Use of the Seas / Naval Part. Good usage of promotions and hatching of high-level units and usage of the magic system + Promotions.
Later still more on my favorite civs which include the sidar and shading. To tired now to continue and elaborate on that points. But will.
