Here is my version.
Tibetans
Monk civilization
-Barracks: No Tracking or Halberdier.
-Archery Range: No Arbalest, Hand Canonneer, or Parthian Tactics
-Stables: Scout line has no upgrades, Knight line upgrades only to Cavalier, has Camel but no upgrade. Lacks Bloodlines and Husbandry.
-Siege Workshop: No Bombard.
-Monastery: No Heresy.
-Docks: No Shipwright, Galleon, Cannon Galleon, or Fast Fireship.
-Blacksmith: No Blast Furnace.
-University: No Guard Tower, Keep, or Bombard Tower.
-Economy: Full upgrades.
UU:
Dharmapala- Inexpensive Light Cavalry/Monk hybrid unit with an attack bonus vs other UUs. Can Heal but not Convert. Can benefit from Fervour and Sanctity upgrades.
UTs:
-Walled Stupa: Monastaries get a ranged attack, and can benefit from Hoardings (Castle Age UT, Hoardings needs to be researched first, which also needs Imperial Age)
-Gongkhang Armouries: Knight line units cost no Gold to train.
Civ bonuses:
-Garrisoned Monks can fire arrows.
-Cavalry get +0/+1 armour per Age, starting in Feudal Age.
-Monks regenerate Faith 50% faster.
Team Bonus:
-Stone Walls have +1/+0 Armour.
Thoughts: It was brought to my attention that Tibet was actually known for itâs heavy lamellar armoured cavalry, that was very effective against ranged combatants. However, Tibet is a very mountanous region, and horsemanship is much more viable in open plains.
The military culture revolved a lot around sacred weapons, specially Swords, and that Monastaries would often keep sacred armouries that were distributed to those deemed worthy among the local population, in case of war. Therefore, I reasoned that Tibet should have decent and cheaply trained Heavy Cavalry, but not to the point that it could resemble something like the Franks or the Huns.
Trash Cavaliers and a Trash UU, would make their gameplay more unique, while at the same time giving them viability in the lategame. For this, they trade a lot of Cavalry upgrades, even Blast Furnace, but would also have the most cost effective Heavy Cavalry in the game, just not to the point that they should overcome dedicated Cavalry civs.
I gave their Cavalry Archer the Ring Archer Armour upgrade, instead of Parthian Tactics, as it would be boring to have another case of Mongol-Hun mirror Cav Archer line. Parthians were also used to open plains battles, rather than mountanous terrain, so their Tactics would not make much sense in Tibet. Tibetans still would have respectable Heavy Cavalry Archer by the lategame, to round out their Trash Cavalry lines, and provide a good Wood and Gold sink.