The passage links an individual vendetta to collective consequences. It begins with harm brought upon the tribe, develops the secret design and threatening warrior portrait, and ends with denials of liability for named deaths. All three stages revolve around a single problem: how can the cycle of revenge be stopped?
The lion portrait and the grazing/watering metaphor do different work. One characterizes individual power; the other explores the destruction that follows its violent use. This prepares the poem’s subsequent sequence of ethical maxims.