What I don't want: Exponential Growth.
What I see: Babylonian Exponential Growth on techs.
What to Change: Technologies are long affairs, projects are much more short term. Other thant he early technologies, the newest findings are much, much harder to figure out, and they are much, much more decisive. Sharing technology means sharing secrets and brining a nation decades foward.
I am ashamed of myself to expand so fast, I feel evil for expanding so fast, and I feel giddy that the 'Mean Forest Tribes of Germanics' just kissed my toes. Barbs should be a nuisense, you gain experiance from fighting them but they wear you down. Independent cities are stronger, and often hold technologies that they keep to themselves. Migrating barbs terrorized civs, Civs evolve over time, changing systems, dynasties.
I want thus: Agressive Barbs, light gray can kill a unit if advancing isn't well planned. Dark Gray can iniciate raids if they see an opening.
Independent cities are trading states without stats and hold at least one or two techs. They also appear after a civ collaspes.
Migrating Barbs are fluid independent city barbs with military techs to learn from. Stirups came from Central Asian tribes and Persians.
If you want, I will start my own game.
also, Vuruchen, the Silk Road, for many thousands of years, was just a collection of barbs. If we do have it as a cradle of civilized thought (+ep and tech to start) then it would be almost, barely, one tile thick until it reaches the Iranian Plateu or the Yellow River.