Since I studied the Timurids for a concept (and for the Tartary concept joke, hehe) I think that in theory if there can be Timurids, they do not contradict the Mongols in the game.
ABOUT THE MONGOLS OF THE RUSSIAN CAMPAIGN:
They are the Golden Horde, the Mongol horde that still had the customs and idiosyncrasies of Genghis Khan’s Mongols in the 15th century, but with firearms, at least to defend their “captured” cities. Their only difference from the Mongols in the game is that in 1315 Öz Beg Khan banned ######## and Buddhism and made Islam the state religion. Although technically the Mongolian base religious building of the game is the Ovoo, the prayer tents and their technology in 4th age “Monastic Shrines” to act as Ovoo, it exists precisely to remember that the Mongols also converted to Buddhism and Islam in some of his khaganates (or at least that’s how I interpret it).
BUT THE TIMURIDAS.-
They stopped being Mongols, they lost all the Mongolian idiosyncrasy and became sedentary. In fact there is a parallel between the Timurids and the Macedonians of AoE2: Both changed radically for one man. The Macedonians were refounded by Alexander the Great, the Timurids were refounded by Tamerlan from the Ilkhanate, which merged 3 concepts: Muslim ####### ###### + Khanate of Chagatai + The end justifies the means.
BEFORE THE TIMURIDS IN PERSIA:
At that time, the Persian region was a Sunni Muslim Sultanate known as the Khorezmite Empire, which became independent from the Abassid Caliphate. In the year 1270, the Mongols conquered this empire, who at that time were “the Persians.” They called the new kingdom Il-khanate. The Mongols of that il-khanate still had the dealings of the Ao4 civ, their shamans had adopted Tibetan Buddhism, they had horse armies, etc.
The detail is that something curious that happens with anyone who rules Persia is that they become Persian. The khans apparently converted to Islam to please their people, in practice they did not respect Islam.
Tamerlane was a khan of another khaganate to the east or right of Persia, the Khaganate of Chagatai. He managed to seize power over the entire Khaganate and then conquered the Ilkhanate. Being a Mongol emperor who ruled two kingdoms, it was not enough. Since Tamerlan, the Ilkhanate stops calling itself that, merges with the territories of the Chagatai Khaganate and creates its own dynasty: The Timurid.
The guy lived long enough to ruin half the world, invading almost every kingdom in the vicinity, from the Delhi Sultanate, to the Abassid Caliphate, and even against the Ottomans. Not even other Mongols were spared, they also declared war on the Golden Horde. In fact, Tamerlane himself had plans to invade China, if not for the fact that he died of old age before completing it.
During the time he was king, with the spoils of his conquests and plunders, he made Samarkand the capital of his empire and filled it with one. a new architecture: Timurid architecture. He built many mosques, madrassas and palaces, and invested in art and sciences.
At the moment, there are no civs with Timurid Architecture in the game. The Mongols recreate the base architecture they had as nomads, and the Landmarks are from the cities they founded in the northern part of China, while the Yuan Dynasty existed.
The Timurids would have their own architecture, and probably considering that the most favored ethnic group of the same khaganate were those currently called Uzbeks, they would speak Uzbek.
That is why I say that there is a clear path for the Timurids, although it should be considered whether they would also cover the period of Babur, the guy was practically Uzbek and was technically a descendant of Tamerlane, only that he later made his invasion and conquest of India.
It could also be considered that they would be the representation of the Tatars of Age II, only without the Keshik, which is now a Mongol unique unit.