It is unusual to have infantry as your general’s bodyguard unit and care needs to be taken to protect them in the campaign. They can dominate the battle field against all other American factions and will defeat the old world factions if care is taken as to their use. The Thunder Brave infantry are not all that useful but the cavalry are a different matter. Later in the game, you gain access to cavalry & gunpowder units. Koitsenko’s are excellent archers who pack a serious punch in melee as well.
Onde’s Men are vital because they are your only anti-cavalry infantry. Apachean braves throw javelins and are capable in melee as well. An Aztec full-stack will soundly rout your full-stack but will they rout the second and third as well? Certain units are rather useful. They are so cheap in fact that you will have no trouble maintaining large numbers of troops while still turning over an enormous surplus in your treasury and this will be the key to your campaign. It’s not all doom & gloom for the prospective Apache war chief though. The Apache warriors are brave & numerous but man for man, they are no match for their better equipped opponents. With the freedom of the North American plains comes the relative in-sophistication when compared to the Meso-American civilisations to the south.