A leader leads by example, not by force.

Not quite, and the confidence is only medium, because the nearest lines discuss a different subject. "A leader leads by example, not by force" is hung on Sun Tzu. The closest passage is chapter IX, sections 44 to 46: 令素行以教其民，则民服；令不素行以教其民，则民不服。令素行者，与众相得也. Giles translates the discipline point in section 44. If commands are habitually enforced in training, the army will be well-disciplined; if not, its discipline will be bad.

The point is consistent enforcement of orders, not a choice of example over force. Nothing in these sections says that example replaces force, or that force is the wrong instrument. The last clause, 令素行者，与众相得也, stays with orders that are habitually carried out. Giles does not turn any of this into example versus force. Calling it leadership by example is a misleading paraphrase. Cite IX.44 on discipline. Do not promote the lines into a moral the text does not draw.