Kerfuffle
King of the Whale Sharks
UA: Empire of the Traders
Spoiler :
Trade routes from and to civilizations you are friendly with provide 50% more 
merchant specialists in the city by 1, and contains one extra merchant specialist slot. However, when built, it immediately reduces your Like Urdnot said, there's too many effects
Plus there's so much gold bonuses that stack together that it's Shoshone split idea:
Comanche
UA: The great expansion
Horses provide double quantity. Founded cities claim all workable plains,buffalo and horse tiles. Per each horse, one unit ismaintenance free.
Claiming all workable plains, buffalo, and horse tiles immediately from settling is way too much, theoretically you could claim every single tile in the workable radius in your cities.
UU: War chief
Replaces great general. Unlike the great general which it replaces, the War chief is only effective during wars. The war chief has 1 extramovement compared to the great general, and doubles the
barbarians.
tbh, it's strange you'd make them ineffective outside of war when you'd give them a buff against barbarians. You might as well just leave them with the generic great general buff of +15% combat strength overall to nearby units. The 1 extra movement and bonuses from pillaging are ok though.
UU: Comanche Raider
Replaces cavalry. Much faster then the cavalryc5moves: 6), and has a 20%
strength while attacking other unit. When stationed on a tile with horses, the horses count as yours(regardless of the tile owner).
You'll need to rename the unit otherwise it'll be "Comanche Comanche Raider" in-game
The 6 movement overall, again, is a bit much especially considering the Keshik, the fastest and most powerful mounted unit in the game, has a base movement of 5. The ability with being stationed on horses isn't that practical, horses are already fairly common unless you have terrible luck and you already get double quantity of horses with the proposed UA anyways.Shoshone
UA: Snake Indians
Units move through plains as if they were roads, and ignore terrain costs on tiles adjacent to mountains. units receive +15%
Using plains as roads is overpowered, that's way too much mobility right from the beginning of the game, especially combined with the +1 movement melee units and civilian units get during wars. A settler could theoretically travel 6 tiles, and I don't know about you, but I'm pretty sure it'd be annoying to have a city spot sniped repeatedly by the AI, especially on higher difficulties like deity, because their settlers can travel so far in such little time.
UU: Band
Replaces settler. Unlike the settler which it replaces, the band hasfood and
culture) or horses(for
production) from tiles for ten turns(may not remove resources from the same tile twice, or from a tile adjacent to a tile that resourcds has been removed from).
This seems too similar to the Sami's unique scout and its herding ability. The AI would also have trouble settling cities because they'll be confused as to how to settle a city with a unit that has combat strength.
UI: Shoshone encampment
May only be built on plains\grassland. +1
Again, you'll need to change the name or it'd appear as "Shoshone Shoshone encampment" in-game
. This UI, however seems interesting, but the extra culture from adjacent terrain isn't necessary, the culture bonus from adjacent mountains would be enough. I'm not 100% familiar with the Shoshone, so I'm not sure about their link to the mountains, so I can't comment on that.
happiness in the capital for every 3 tiles discovered in the previous turn. All ancient and classical era units receive +1 
Great Work of Writing in a city gives +5 XP to units built in the same city (Max +15). Conquered cities have a free 
Faith and contains a single Writer specialist.
Declaration of Friendship increases income from 
