Thus, Li Mao would understand that the Bai family was unwilling to stir up trouble. It wasn't that they lacked the ability to create trouble for him, and he would realize that even though the Bai family had only a widow and orphans left, they were definitely not powerless.
Li Mao needed to feel pain, to feel fear, and to know just how ruthless the Bai family could be. Only then would he be truly wary and scared from the bottom of his heart.
Otherwise, if Li Mao harbored thoughts about the Bai family or caused trouble for the Bai family army stationed in the southern borders without reason, it was not something she wanted to see. She needed the Bai family to be safe and the Bai family army to be successful. Thus, Li Mao had to be subdued and even made to protect the Bai family and their army.
In this way, the letters that Li Mao dreaded would also temporarily remain hidden.