Probably no easy way. Generally, individual units can be encouraged through iAIWeight in Civ4UnitInfos.xml, but, for settlers, probably also for workers, I don't think this will make much of a difference, if any. I'm guessing that early-game settlers mostly get produced through this function call in the DLL. The main precondition is that at least one worthwhile city site needs to be known to the AI (iAreaBestFoundValue > iMinFoundValue). If that's the case, then the problem is probably that AI code higher up in AI_chooseProduction is keeping the AI cities busy with other tasks – wonders, other buildings, units for defense, exploration or warfare. I haven't played FfH2, but I think there are lairs and spell-casting units. I could see those or other additions in the mod(s) distract the AI from settlers and workers. In the MNAI-U mod, which I assume has the most sophisticated AI for FfH2, I see that a conditionIs there a way to make the AI expand more? E.g. tweak preferences so they're much more likely to build settlers/workers, use settlers to found new cities, etc.? Preferably a relatively easy way. I have options to stop them crashing their economy (e.g. no unit maintenance) if need be.
I'm asking because I play high-level FFH2, but always find myself leading in score pretty quickly because the AI is atrocious at expanding (no matter which modmod I play). It's quite frustrating.
!bRoomToGrow
has been added, which apparently means that, once the AI has at least 2 cities, it will not consider a settler so long as there are improved tiles to be worked and the happy cap isn't yet reached. That said, a second, lower-priority rule for producing settlers has also been added.I think you'd have to use Debug mode (Ctrl+Z with the chipotle cheat entered in CivilizationIV.ini) to watch what the AI is doing when it should be producing workers and settlers – and then look into deprioritizing those other tasks. There might be ways to do that indirectly through XML changes, but, more likely, those would have to be DLL changes. It would also be good to verify that the AI succeeds at exploring city sites; that can be checked by hovering over tiles holding down the Alt key. The help text should show a yellow X when a tile is a planned AI city site. (Some mods will also highlight such tiles through colored circles when in Debug mode.)