The problem is not tilting the field towards the AI, the problem is tilting the field and without realizing altering the game that way. Simply example, in Civ 3-4 on medium difficulty wonder building was to some extent sensible. On high difficulty it was stupid. Hence the AI bonuses altered the game by removing some possible options what to do.

The same might be with extra pioneers, if the number of city spots is 5 per player on medium difficulty one might have the option to spam risky and get 6 spots or build military to helpquesting and be satisfied with 3 or 4. If AI starts with extra pioneers the only option might be to spam risky, because if one does anything else one ends up with just 1 city instead of 3 or 4. In civ 5 they somewhat adressed the problem by rmoving any AI production bonuses when building wonders. (That might be a good idea for Fallen Enchantress)

Initial perks are bad, because they enforce specific player reactions and limit the choice of stretegies. Drastic example if each AI would get as start bonus 5 full leather spearmen, the AI logic would probably conclude upon meeting the human player around turn 15, that its a hell of a good idea to bully him around or just conquer him. The human player would not have any early game choices left, as his only choice would be to build up defense, so he survives the initial onslaught. But after winning that one crucial battle, the 5 AI spearmen are dead and the AI bonus is gone, making the game drastically easier for the player afterwards.

5 bonus pioneers for example would grab land and be of no use. The humans players counter would be to use his sovereign and first champion to attack the 5 pioneers before they settle. Doing anything else would be stupid and lose the game. Afterwards the AI bonus is again gone and the human wins.

On the other hand, if the AI just gets an economic bonus, the AI might turn that into additional spearmen to harass the player. Or he might grab additional land. Or concentrate on boooming his economy. The human player is not forced into a specific strategy and yet its still chellenging. And it remains challenging (I know, you would not suggest 5 pioneers or spearmen, but 1 has a similar although lesser effect.)

While ideally it would be nice to increase game difficulty with a more competent AI, without altering game mechanics and keeping all options open to the player, that's unfortunately wishful thinking. If we want to play more challenging single player games, that means higher levels and tradeoffs to be made. To avoid excessive penality to player experience, these need to be based on an analysis of both game mechanics and AI weaknesses, not on what "should feel right".

I have been playing the game since 1.20 came out at both ridiculous (mostly wins) & insane (no wins) and simply sharing my analysis:

- the game is too "unstable" / "divergent", ie too favorable to the top dog and too punishing for the underdog, ie gives only benefits for being big (tech, production, resources, military, diplomacy...) without any drawbacks such as those found in civ (unhappiness, troop morale, inflation, diplomacy / reputation / AI wariness, trade / tech agreements...)

- AI being so weak at initial expansion, on ridiculous the player can attain top dog position fairly quickly and set the game's divergent dynamics going sufficiently in his/her favor that it overwhelms ridiculous AI "long term" perks (HP bonus, economics, ...)

- however, on insane AI gets such large "long term" perks that it can simply sit on its arse with a single settlement and win the game no matter what the player does, even if he/she has the rest of the map with a dozen settlements

Therefore:

Im fine with that, tried a few days ago a game with AI having 500% HP bonus and scaled down economic bonuses. Would have been intersting challenge, if the AI had been aware of its own bonus.

But that is a problem of the game mechanic and it would be better to be adressed with drawbacks than AI bonuses.E.g. my last game i had the drawback of early expansion in the form of AI building an outpost near my frontier city, with a drake in his radius. The drake of course ignored his outpost and incurred "costs" on my side.

That of course are good reasons for increasing start bonus (though the AI has start bonus, with 1000 gildar he should be able to rush enough pioneers).

Sure.

Engineering Faction ability (cost 1) : unlocks 3 unit design abilities, at Labor cost.
- Builders will allow the unit to build an outpost. Unit disappear once the outpost is built
- Settlers will allow the unit to settle a new village. Unit disappear once the village is built. The ability is unlocked with Civics Tech
- Road builders will allow the unit to .... well, build roads. The ability is unlocked with Trading Tech.
Note that the basic Pioneers (at Population/Gold cost) are not modified but still useful.
Fortifications can be built in all the Engineers cities, and they're always upgraded (more troops + unit bonuses). They become available as soon as a workshop is built in the city. Only the Fortress city type can build Fort / Castle buildings, which are also upgraded (more troops + unit bonuses).

So ... Engineers can train units able to settle a village, to build an outpost, or to build roads. These units can wear armor, weapons and magic items, and they can have mounts and other traits.

Typically : mounted outpost or road builders with the Scout + Sneak traits

FE V1.3 disclaimer : I thought SD had upgraded the "automatic road building system" between cities, and to Outposts and that road builders would become less important than before ... Finally, I'm not sure at all that anything has changed on automatic roads building, considering my current game.

IIRC Derek stated that he dropped the pop cost due to issues with the AI draining their settlements of inhabitants.

I'm a bit afraid that it will happen with gold cost that they stay broke for ever from trying to spam more pioneers...

No worry, on high difficulties AI starts with something like 1000-2500 gildar.

The AIs eventually do produce settlers, but are a bit clueless about what to do with them... AI settlers mostly end up hanging around their favorite uber monster's lair

In my current game I ran out of gildar and couldn't make more Pioneers.  It seems like the Wealthy Sovereign trait is a required-take, now more than before.  The AI gets a lot of starting gildar at higher levels, but I'm not sure it knows what to do with it.  Every time I talk to them in the early game they've got 1500-2500 gildar.

An AI's life is full of confusing, difficult choices

There are some good ideas here, and thanks to Kael for explaining the difficulties.

I preferred it when pioneers cost population. It makes the population growth mechanic a lot more important. The difficulty stated is that the AI was playing badly with this. This seems an easy thing to fix? Just give the AI some rules about when to build a settler, that weighs up the advantages of doing so against the costs. I imagine a scaling factor that makes it very unlikely if the town is small, and quite likely if the town is very large. It isn't that complex a heuristic to build.

If the end result is that pioneer spam is reduced, that is a good thing.

I also like the idea of splitting out the tasks that a pioneer can perform into different units. Engineers to build outposts, pioneers for new settlements, etc.

I think they should write into the difficulty code that the ai will have a higher chance of taking the "wealthy" trait the higher the difficulty one selects. Practically automatic on INSANE.

Either that or rewrite the wealthy trait because right now it's just too overpowering with pioneers being created from gold.

Maybe a solution for settlers would be to require an influence cost. Sovereigns would need to have a small base influence income, and you could get one time influence bonuses for feats such as winning battles against the odds etc... in addition to existing mechanisms. And it would balance out a bit with henchmen: if you spend your influence on settlers, less to spend for henchmen.