I think Carthage is a no-brainer for you, but you're the best player here. (China is also incomparably better in your hands than in that of the AI.) I'd guess that they would have been reduced long ago if 175g made them such a no-brainer for everyone else. Again, they're top tier -- but some civs have to be. Otherwise why not have a poll, see who comes in at the top, and auto-nerf the top 4?
I may have misunderstood Gazebo's intent re: this thread, but... to me, knocking off 50-75g from Carthage's founding bonus is not a "simple number tweak." It's a major nerf. The AI may not use that as well as humans do, but it's still what they use best in the early game.
Simple != small, simple = change numbers in XML/SQL. Existing functionality, but different numbers.
G