This Yan Zhongjie is both loyal and honest. Just by looking at his name, it's clear he's a die-hard loyalist of the Immortal Palace, a standard model of a distinguished official. As the Prefectural Governor of Changshan, he can rally the hearts of the entire county, using merely a few thousand rebels to delay the tens of thousands of rebel troops, earning more battle merits than the Royal Army.
However, the Immortal Palace is too weak; eighty thousand fought against twenty thousand and suffered a great defeat with bodies strewn across the fields. Thus, after holding Changshan for several months, when supplies ran dry, the rebel army broke through and massacred the city, and Yan Taishou's entire family was hung and executed for public display.
But the Yan family hadn't been wiped out, because Yan Changshan still had a brother, the former Pingyuan Guard of the Gen Kingdom, Yan Wenzhong. Yes, another 'Zhong', another 'Guard', highlighting the family upbringing.