I played couple of extra turns to even them up.
Research went Railroads -> Scientific Method -> Biology (8 turns remaining).
This turnset was mainly war so there might not been that much micro management. Killing your enemy really takes all your time
So... I started by upgrading units on first turn and declarin war against Qin and Genghis on second turn.
Soon we take capital's from both of them. Qin had Scotland Yard, Great Wall and Mauseloum in his capital.
In between, we are reminded again that this variant is not so easy to fullfill. We didn't get much positive modifiers for declaring everyones best friends
Here is the razing part. We are too close to domination limits so can't keep them.
This has earned us little more help on battlefield. Too bad we didn't have him before this war, would have helped a lot.
Qin became vassal of Genghis and neither of them have been willing to capitulate. Here are the remaining defenders that we can see.
We have enough troops to conquer these cities, but most of them are injured. Our war weariness is starting to become a real pain.
We got Great Prophet and he is waiting with GM in capital. We can start golden age and make necessary civic changes.
Good luck!