The Army of Dothrac is considered one of the fieriest in the world, even the Tethyr Knights don’t tend to cross the them. The Dothraci do not consider themselves knights or even Bannermen, they are warriors. They would never dishonor themselves by wearing armor and are always mounted on a horse. Their horse is their “divine attachment” and they join themselves to their horse through a ceremony called “conjunction” after which, their bond with their horse is one similar to marriage.
The Dothrac Army is quite small in comparison to the size of the Nation-State, but due to their intense training, 1 Dothraci is the equivalent of 5 Tethyr Knights. There are no ranks, all Dothraci are considered equal and they allow leaders to emerge naturally.