Well, the concept of Variant has changed. Variants are no longer just the original four civs sharing 99% of the tech tree with other civs, plus a few unique units (like Joan of Arc, Zhu Xi’s Legacy, or Order of the Dragon).
Starting with the Knights Templar and Lancaster, variants can now be something distinct while still sharing one or two elements with the base civ (such as language, a wonder, or architecture).
That said, after working on a Timurid concept (Timurid Civilization Concept), I can say that making the Timurids as a variant wouldn’t be very possible at the moment.
For start, the Timurids:
- Had 2 official languages to pick: Chagatai (part of the army), Persian (for the court and writing, promoted)
- Had an unique architectural style: Persian-Timurid architecture (featuring tiles, massive vaults, and massive iwans).
- Had their own unique units (Chagatai Horse Archers, Bactrian Fire camel) and a system of vassalage and slavery.
- Built many landmarks in Iran, Uzbekistan, and Afghanistan that still stand today.
The sticking point is the architecture: there is currently no Persian architecture in the game. The only ones who could feature Persian architecture are, curiously enough… the Persians… or rather, “Iran” as a new civ.
Shared Units or traits - variants. Now, the Jin Dynasty also broke the tradition where only variants shared units with their parent civ. They possess the Traction Trebuchet—alongside the Mongols—because the Mongols stole the blueprints and engineers for this unit from the Jin; yet, the Jin Dynasty is a variant of China, not of the Mongols.
For that very reason, I think that in the future, the Timurids could be a variant of Iran (since they controlled Iran for a century) or of the Mongols—given their origins in the Chagatai Khanate and the remnants of the Ilkhanate.
Of course, they would need to feature “Persian architecture” with Timurid elements (blue), and their language could be either Persian or Chagatai.