How was Cortes able to create a large army of natives?

Several tribes, especially in the coastal areas had suffered badly by the Aztecs. And they welcomed the chance to go against them. Cortes did not have to do much convincing. After defeating one tribe known as being very fierce, even the Spaniards were outnumbered one to 40, many tribes just offered themselves as allies to Cortes. Also he had the great help of a very intelligent native woman, the Malinge.