4 ideas
In 1524 the Kaqchikel lords of Iximche received Pedro de Alvarado peacefully and sent warriors with him against their rivals, the K'iche' and the Tz'utujil. Once those enemies were broken, Alvarado turned on his hosts and demanded heavy gold tribute. The Kaqchikels abandoned Iximche and fought a guerrilla war for years, then submitted to forced labor and tribute; their king Cahi Ymox was later hanged by the Spaniards.
A local power that helps an invader defeat a shared enemy loses its bargaining position at the moment of success. Its warriors were valuable only while the rival still stood, and afterward it is simply the nearest remaining target for extraction. Using a foreign force to settle a regional rivalry transfers the rival's fate to yourself one step later.
The chronicle records a plague around 1519–1521 that killed huge numbers of Kaqchikels, including lords, before any Spaniard reached the highlands. Disease moving ahead of the invaders emptied the ranks of fighters and leaders and disrupted succession. Military conquest then fell on societies that had already been hollowed out.
Read the Xajil record less as neutral history than as a family's evidence file. It records its origin at Tulan, its migrations, its lords, and its victories in order to fix the lineage's rank and its claims to land and authority. The same logic kept the text going into colonial times as a ledger of the family's standing under the new regime.