Complex sentence: In early 211, Cao Cao ordered Zhong Yao and Xiahou Yuan to lead an army to attack Zhang Lu in Hanzhong and they were due to pass through the Guanzhong region along the way.
Split into simpler sentences: In early 211, Cao Cao ordered Zhong Yao and Xiahou Yuan to lead an army to attack Zhang Lu in Hanzhong. They were due to pass through the Guanzhong region along the way.