What does it mean to say, "A general with a weak liver will be able to make plans and plans; a person with a weak head will be able to make officials happy." What does it mean?

From "Reading the Medical Classics", a Chinese medical book written by Shen Youpeng in the Qing Dynasty.

Original text: The heart is the official of the monarch, where the spirit comes from; the lungs are the official of the life and pulse, where the management of joints is; the liver is the official of the general, where the planning comes from; the courage is the center of justice. When an official is appointed, the decision will come out; when the person is in trouble, the minister will make him an official, and the joy will come out.

Vernacular: The liver is an organ like a general, from which strategies come out; the liver is an organ like an envoy, from which joy comes.