Before the 225 campaign Ma Su said the south relied on its remoteness and would rebel again after a defeat. The way of war was hearts first, cities second. Zhuge Liang accepted it. After the campaign he used local chiefs and did not leave a large garrison.
The speech is in the Xiangyang ji, quoted by Pei, not in Chen Shou’s main text. It is still early, and older than the novel. It explains administration: how to hold a place that revolts. Seven captures are a later theater of the sentence. Do not use the seven captures to prove the sentence.