I've been wondering what I can do about population growth (for all factions) in my 1-turn campaigns. I remember there wasn't enough growth in 2.1/2.5 to keep up with how many units the AI likes to recruit. There would be lots of small towns stuck at a population of around 400, which of course was awful for their economic/military development. I don't want to go back to that.
But in basically all of my 2.6 1-turn campaigns (I don't do 0-turn, so that may be different), regions grow very quickly. Within maybe 60 or 80 turns, just about every region has a large city -- for whatever reason, the AI doesn't build huge cities that much (or they'd rather build lots of other expensive long-term projects first), even when the populations are well over 24,000. That seems like too much to me, but I don't know what changed or what I could do about it. If I could, I'd like to get maybe 0.5%-1% less growth overall; not anything major, just a small tweak that would stretch out the growth a bit (in some/most regions) so there's something to look forward to in a somewhat longer campaign. And basically just get some more diversity in the middle of a campaign, with some large towns, some cities, large cities, huge cities -- you get the idea, I hope. Maybe they would have more time to make other improvements at each city "level" before they decide they "need" to increase the level (however that happens), so they might do more of that too.
The markets/barracks/farms/wells/etc. that do anything about growth all seem to have small, incremental improvements (0.5% at a time) that wouldn't make such a big difference, but I suppose altogether they do add up, at least once the settlement is big enough to actually build them in the first place. I just don't remember any of that being any different in 2.1 or 2.5, so I don't know where to look for things that seem to amount to 3/4/5% more growth, which I could scale back just a little bit without eliminating the effect completely. The "population growth measures" building tree is a bit more drastic, and I have cut that back slightly already. But the AI doesn't build that everywhere anyway, and the big jumps aren't available until you're already at the "city" level, so I don't think that would account for what I'm seeing.
The "base farm level" isn't any higher in 2.6 1-turn (compared to 0-turn), by the looks of it. But if that's still the issue (because of recruitment differences), what would I do about that? Just lower some of those numbers in "descr_regions"? Is there any reason why that would be a bad idea? Does that affect the income in a region too: would everyone be poorer if I lowered the "base farm level"? Or more generally, besides fiddling with the effects in the "export_descr_buildings" files, is there anything else I can do about it?
EDIT: I should probably add that I use "huge" units. I don't know what people did while testing 1-turn campaigns, but I figure that would make a difference.