Yes, but we would need to be able to limit Building, Units, Wonders, etc to a given civ to change this Euro-centric default, and also true customizable tech tree, on a civ per civ basic.
For instance, I have one question for my own mod. Some units were never used by some countries. Should I let the unit available, with a kind of generic units, or will the civ have to do without them? But then, what's the point of discovering the tech?
Take the Aztecs. Should I gave them cavalry units? Yes, Aztec had no cavalry. Because they had no horses. What would have happened if they had had horses?
Limiting the units (at least) to unit actually used by a civilization would give very specific civ, and provide real challenge for some of them, but I'm afraid it will unbalance the game to much.