Of higher rank than the Keshig and Tarkhan castes in Mongol society are the Noyan — the governors and commanders of Mongol forces. The Noyan distinguishes itself as being one of the few "Chivalric Order" units capable of boosting the attack and/or defence of nearby friendlies, and can also attack like a cavalry archer. Noyans, however, are hard to come by — they are costlier and train far more slowly, meaning that you can't really have a whole army of Noyans. The best way to use them would be the same way you would use Christian Chivalric Orders — as the leaders and escorts of your armies to improve their capabilities in the field. Furthermore, Noyan can be recruited only from the Nobles' Court, so it will take some time for you to raise these men to lead your armies to glory.