Why didn't Gongsun Shu assassinate haing s ngor?

The so-called three things, and after the assassination of Lech and Cen Peng, Liu Xiu wrote a letter to Gongsun Shu, urging him to pull back from the brink and surrender as soon as possible. He mentioned in the book that after the death of Lai He and Tseng Peng, he said that he would be transferred to Gongsun Shu's wife, children and family to ensure that he would not be hurt when he surrendered. When he said that he would persuade him to surrender, he actually warned his family's life. You will be the first day, and I will be the fifteenth. Later, Gongsun Shu did not dare to send assassins. However, he is still unwilling to surrender. At last he died and his family was wiped out. The people of Chengdu also suffered greatly, and were plundered by the soldiers of haing s ngor.