forum.wgcwar.com

.. until there is an official list I use my Apache & Comanche lists. Although the era of triumph corresponds to that of DBA; So 3000BC - 1500AD I found some lists that end in 1770AD.
Vásquez de Coronado was an early visitor der Apachen about 1540AD. After that, runaway Spanish horses They spread all over the country and became undomesticated mustangs.
The Apaches learned quickly & became mounted robbers. During the pueblo uprising in 1680, the Apaches supported their pueblo brothers. In about 1650 the Comanche separated from the Shoshones & spread over the southern plains & become enemies of the Apache. In about 1724 the Apaches had been routed from the southern Plains. From 1750 the Comanches dominated Texas.

all tribes with the all mounted option for raids
Apache 1500-1770, IR: 2 MR: 2, dry, hilly
6-12 horse bow(Gen), - abtet1600
0-12 warband or skirmishers, all
0-8 skirmishers,
0-8 bow levy, all

Comanche 1650-1770, IR: 2 MR: 2, dry, hilly, forest
6-12 horse bow(Gen), - abtet1650
0-12 warband or skirmishers, all
0-8 skirmishers,
0-8 bow levy, all

Plain Tribes 1720-1770, IR: 2 MR: 2, hilly, forest
6-12 horse bow(Gen), - abtet1720
0-12 warband or skirmishers, all
0-8 skirmishers,
0-8 bow levy, all

I think you're about 80 years too early. In 1680-1690 horses were still quite rare among Indian tribes in Texas; the full-blown horse culture of the plains indians didn't exist then, not even for the Comanche. Very likely it was many generations of horses after the Pueblo Revolt. As late as 1725, Comanche were still reported as using large dogs as beasts of burden because of lack of horses.

Even when we finish up the North American army lists, I don't foresee that we will be extending them to the horse cultures of the North American plains. That's 250 years after the end of our period of interest; they will have no common enemies with anyone save themselves. Plus the fact that their culture of dispersion and raiding is much better suited to a skirmish game simulation than it is to a mass battle game like Triumph.

None of which is a barrier to your enjoying yourself as you wish, of course! Just being up-front about the fact that Triumph will not be going that direction.