Ok, the Chinese UHV is doable if the player has a decent starting place with some food resources. I was lucky to have a 2 gold/2 floodplains city which hosts both religions, so that solved the research early on and finance later. I was sloppy once I hit music (in 470AD!); in retrospect I could be more focused.
Several things to note apart from the RFC guide:
1. Do not found cities too far north, especially to the northwest. Dealling with the mongols later is ok, but when the Russians spawn they may flip those cities, which is a pain when the player tries to build temples/cathedrals. Instead, expand to the South.
2. Persia is an opportunist. It will spawn close to China, instead of India. Make sure to get Bronze working and the Wheel before Calendar, and have 1-2 spearman or the ability to whip 1-2. An early DOW when China only has warriors is not fun. But their presence makes the game easier later on...
3. Trade for construction in order to build the Great Wall. It is almost a must for RFC RAND, since the barbarians are a lot less predictable. Even if that means sacrificing music. We need it.
4. Instead of building the 6th, 7th and 8th settler, take those cities from the Persians if possible. The Persians will not have a huge army. Watch the mercenary situation and hire those instead of letting the Persians have them. 5 Axes, 5 Catapults and 5 Spears are enough in my game, with reinforcement coming. Persian cites are less likely to be flipped by Russians or Mongols, so this is safer than building your own cities.
5. When Russian spawn (hope that they did not flip your cities, otherwise UHV is practically impossible), gift them sailing and open borders, convert them to your state religion, and they will be fine until the Mongols spawn. When the first UHV is fulfilled, build lots of elephants.
6. When the Khan comes, get Russia to DOW on them (you almost definitely have a tech on the Russians). This distracts the Keshiks away. Get all the elephants and kill the Mongols. Turkey may flip one of your Persian cities; give in. We do not want any more wars.
7. Never trade for engineering, so you can train spearman. If you are desperate, you may even blow up your iron/copper so you can train warriors... Tech paths should be Code of Law-Civil Service-Paper-Education-Gunpowder mostly for deterrence. after that scratch research. Build military everywhere.
8. Mercenaries count towards your army count.