After a bit of research, here’s a unit roster that could work for a specific civ like Uzbeks, or a more general Tatar civ.
Fires faster the closer the target is. Extra high multipliers against light cavalry.
Mergans would serve as the Uzbek musketeer equivalent. Could be depicted with a Kalpak hat as shown below.
Many depictions of central Asian firearms have a bipod or monopod. This could be depicted by giving them extra range in exchange for a little less health. Being armed with a sword instead of a bayonet should mean they follow the pattern of higher base attack with a lower cav multiplier.
Melee infantry armed with scimitars like shamshir or kilij.
Navkars were the main soldiers of the Uzbek khanates. They could serve as fast and strong Hussar equivalents.
The most elite warriors of Turko-Mongol societies. Could be a very powerful cataphract like heavy cavalry unit similar to a Lifidi Knight.
These were elite Mongol warriors that became the ruling class of khanates like ##### and Bukhara. They would serve as powerful light cavalry units.
The current depiction of Zamburaks in the game as weak light cavalry is extremely far from reality. Zamburaks actually functioned as highly mobile artillery. Indians already have Howdahs for their light cavalry, so there is room to give them a different function that works better for an Uzbek civ. If they were given a design similar to Rifle Riders, they would fit in very well with an Uzbek civ. They should also deal siege damage to reflect the fact that it is a cannon. Rebalanced costing and a limber animation may be needed to keep them balanced.
There are currently Great Bombards and L’il Bombards, but no regular Bombards. This could serve as a slow firing but powerful Falconet equivalent for all civs that used Turkish sourced artillery (Ottomans, Mughals, Persians, Somalis, etc).
The Mongols used various gunpowder weapons in their conquests and this could be represented by sharing the Hand Mortar unit with China. May not be necessary depending on the functionality of Zamburaks.
Being in a landlocked region makes finding a navy very difficult, but the Tatars did occasionally use boats to cross rivers and fish the inland seas.
They had access to fishing in the Aral and Caspian Seas.
These were Novgorodian pirates that operated on the Volga. They generally raided the Tatars but could be co-opted to provide them with a navy. They could function similarly to the Battle Canoe.
The Caspian Sea is a significant body of water that the Uzbeks bordered. It would be reasonable to assume that it could support moderately sized ships like Galleys. The picture below is just a ship named “Tatar”, it is not actually a Tatar ship.
Russia brought a significant naval presence to the area with the Caspian Flotilla and Aral Flotilla. The Persians also had their Northern Fleet in the Caspian. Some of these ships could supplement the Uzbek navy.
A Mughal alliance could give them access to War Dhows