Uzbek. Hear me out, at first glance Uzbek looks like a dine-a-dozen horde, but it is actually one of the most versatile tags in EU4.

First off it is a horde, the strongest gov for WC in EU4. It has the best units at the start of the game. It has horde ideas, already in the top tier NI group.

Second, it has a unique tag-switch decision into Bukhara. The main bonuses are that the tag grants decent perm-claims, changing your overnment to Iqta, and avoiding the nasty stability cost. If Horde is an S government early-game then Iqta is an A. The early autonomy drop is just that powerful. Finally the 500 or so admin you save will push you years ahead.

You're already the big bully in the region. The only other large tag is the Timurids who will blow up 90% of the time. This means some of the fastest expansion early game.

Your religion is Sunni. Steppe Horde's greatest weakness is their inability to convert land efficiently, especially early-game. (This is why forming Mughals asap as Timurids is so important.) Uzbek avoids this issue. You start surrounded by Sunni land. You can conquer to your heart's content and the second you need to start converting? Switch to Bukhara. Sunni is also the best religion to switch from. With the Dhimmi estates converting yourself to your preferred religion is quick and painless, having quick access to Christianity to the West and Confucianism to the East.