The Sioux armies are mainly composed of Cavalry units. They have the strongest cavalry units of all of the Native American civilizations, but they have mediocre infantry. One of the most unique and important ability of Sioux is that they don't need to build houses; they already have 200 population cap from the very beginning of the game, their houses are replaced by Teepees, which instead of increasing population, increase hitpoint and attack of nearby units.
Their armies consist of mostly cavalry, as their infantry are mediocre and do not possess artillery, but the armies are quite balanced too. Ranged infantry can be countered by Axe Riders, Dog Soldiers, and Tashunke Prowlers. Heavy infantry can be beaten with Dog Soldiers and Rifle Riders. Cavalry can be destroyed with Bow Riders and Rifle Riders, and artillery can be countered with any unit. Buildings can be destroyed by the use of the Fire Dance or any cavalry with high siege damage. In treaty their best ally is Chinese for Chinese can gives them most counter against most units except the cavalry, cheaper units, artilleries for knocking down buildings and economy support while Sioux can give cover for the Chinese against cavalry.
WarChief Bonus: Possesses aura that increases the speed of nearby allied units
There are six cavalry unit types available to Sioux. There include:
The Sioux War Chief - The Sioux war chief is one of the fastest units. They have an aura that increases the speed of nearby allied units. With a shipment they can also boost attack of nearby allies and have Stealth ability.
Axe Rider - A powerful hand cavalry. It has high attack, low hitpoints and fast speed. It has higher attack than most cavalry, but due to low HP, it must be guarded by other units. This cavalry is good against light infantry and artillery.
Bow Rider - A powerful ranged cavalry. Like all ranged cavalry units, they are good against other cavalry units, and are also useful against Heavy infantry units.
Rifle Rider - It is a powerful ranged cavalry unit, the Sioux counterpart of the Dragoon. It has the fastest rate of fire of all ranged cavalry units and one of the fastest rates of fire in the game, with 1 shot per 1.5 second. They are good against Heavy infantry and cavalry.
Tashunke Prowler - It is a hand cavalry unit which increases in hitpoints as they increase in number, but they have a build limit of 12 but can be increased with Home City Shipment. They also have area of effect damage and stealth ability. They are good against light infantry and artillery.
Dog Soldier - The most powerful cavalry unit available to the Sioux. They have decent hit point, excellent speed and high attack. As a lancer cavalry unit, it is good against Infantry units, and as a cavalry, it is also good against Skirmishers, Archers and Artillery.