One last civ suggestion:
Yuezhi/Kushan Empire:
The idea is to have a nomad civ in Classical age that can make things more interesting in Central Asia before the Turks spawn, replacing the some of the barbarian/indy spawns (including the Silk Road and its cities) with a proper civ to develop the area and spread Buddhism (and also building the Salsal Buddha wonder, which I personaly rarely see). Given that we have art for this civ, including its LHs in History Rewritten, we could easily add it.
Spawn/Location: 400 BCE/Dunhuang (earliest mention of the Yuezhi)
Leader: Kadphises, Kanishka
Color/Symbol: ?
Expansion stability: given that the Kushan Empire was a result of the Yuezhi migrations, the idea is to have some core shifts during the game. Initially, the core would be the area of Gansu province in China, with historical expansion in the Taklamakan Desert and Bactria. After conquering a city in Bactria, the core would shift to the Hindu Kush and Gandhara, while the historical areas would be argably the territories conquered by the empire in its
maximum extension, including all the Indus Valley and significant portions of East Persia and North India. Ideally, the historical expansion would shrink dramatically by 450 CE accompanied of barbarian spawns (White Huns invasions) to induce the collapse of the civ.
UP: The power of Syncretism (non-state religions don't affect the stability or provide unhappiness, + 1 culture and + 1 gold per non-state religion).
Refers to the cultural syncretism of the Kushan Empire, a mix of nomad Indo-Aryan, Bactrian, Persian, Hindu and Greek heritage that greatly promoted the spread of Buddhism and established commercial links with far away empires, including China and Rome.
UU1: Avaska (replaces Horseman, starts with Mobility promotion and doesn't have combat penalty when attacking cities).
Is the same barbarian unit that currently spawn in North India. Although this unit is more properly Indo-Iranian than Yuezhi, I think that fits well with then, given that the early Kushan state adopted armored cavalry corps after conquering these peoples.
UU2: Trishula (replaces Spearman, + 25% attacking cities)
or Yukhuna Purma (replaces Horse Archer, doesn't have combat penalty when attacking cities)
I'm not certain about this second UU, so suggestions are welcome. The first unit comes from History Rewritten and is certainly ahistorical, however represents the Indo-Greek infantry tradition in the area. The second is representative from early Yuezhi times, when their armies were made from horse archers. The name comes from Europa Barbarorum and supposely means Yuezhi Cavalry.
UB: Gandharan Stupa (replaces Pagan Temple, can be built even if a religion is present, give + 1 happiness)
or Carved Statues (replaces Monument, + 15% production when building religious buildings or wonders)
Again, I'm not certain about the UB and would love some suggestions because I couldn't find any good candidate. The first is a reference to the Gandhara Archictecture with the Greek-Buddhist blend that was influential in the development of following stupas and pagodas. The second represents their tradition of carving Buddha statues in mountains (of which the more famous and monumental were the Bamyan Buddhas).
UHV:
1)
The Kushan Empire: have a capital in the Hindu Kush region with a developing culture by 30 CE.
2)
The Centerpoint of Major Civilizations: have Open Border agreements with four different civs
or have trade routes with four different civs by 200 CE.
3)
Greco-Buddhist tradition: build Salsa Buddha and eight temples (any religion) by 400 CE.