I started reading The War for Mexico's West by Ida Altman. In the second chapter she states that Nuño de Guzmán recruited troops from central Mexico and Michoacan for his entrada into the territory that would become New Galicia (Jalisco, Zacatecas, Nayarit). Perhaps not in Guzmán's case, but in others, did internal fighting arise between these mixed regiments of formerly hostile groups? Did the Spanish keep these groups in separate camps? What prevented these groups from turning on one another in the heat of battle?