Complex sentence: Clans of Hawazin that could not leave with rest of the tribe during the conquests were named Otaibah, and they amalgamated into a much larger alliance with blood relatives that descend from the same ancestor.
Split into simpler sentences: Clans of Hawazin that could not leave with rest of the tribe during the conquests were named Otaibah. They then amalgamated into a much larger alliance with blood relatives that descend from the same ancestor.