@Toffer90: you said you made Nightmare a lot easier compared to the last JosEPh_II's numbers. Have you set Nightmare back to difficult again?
That was reset in the TB commit I waited for. I believe a lot of the easiness factor you describe is better adressed with the upcomming C2C v39 AI overhaul TB have planned for (He said even before v37 was released that he planned an AI overhaul for v39). We may want to make difficulties harder than they currently are until we get the AI better.
The only thing I made easier when I started out was:
<iTrainPercent>110</iTrainPercent> → <iTrainPercent>135</iTrainPercent>
<iConstructPercent>110</iConstructPercent> → <iConstructPercent>135</iConstructPercent>
<iResearchPercent>225</iResearchPercent> → <iResearchPercent>135</iResearchPercent>
And I did it as a temporary solution because I was making some major changes to tech vs building cost across all game options and if I hadn't normalized those values you would have had techs take way too long to invent for the difficulty to be playable at all. I was waiting for a new handicap tag that made it possible to adjust the research cost for the AI based on the difficulty the human player was on instead of doing it the other way around. That way gamespeeds are the same regardless of what difficulty you play on.
The equivalent to the tags above is now set from:
before I changed anything related to balance → how it is now:
<iAITrainPercent>100</iAITrainPercent> → <iAITrainPercent>44</iAITrainPercent>
<iAIConstructPercent>100</iAIConstructPercent> → <iAIConstructPercent>58</iAIConstructPercent>
<iAIResearchPercent>100</iAIResearchPercent> → <iAIResearchPercent>79</iAIResearchPercent>
A lot of other difficulty factors have been changed too, and we might want to increase the difficulty step between the difficulty levels for some of them based on user feedback.
Edit: Had a look at your game, and I see you play with start as minor civs, this gameoption breaks the AI in so many ways that it should be removed from the game imo.
AI in a perpetual state of war makes them real stupid in many ways, they will practically give up on developing their nation while in a war that seems overwhelming unless they have many cities that can be spared from the war effort.
I see you also use the downsizing is profitable, it's ok as long as you never split up units before selling them as this is an exploit. The option kinda requires you to put a self imposed restriction on how units can be disbanded. Edit: Didn't know the gold amount had been scaled correctly.