Why would “I saw a lion” be weak if intended solely for a person with bad breath?

Conditions of Excellent Metaphor: Good Simile, Clarity, and Imaginative Force

• Bad breath is not a customary shared quality associated with a lion
• Because the intended resemblance is exceptionally familiar
• Because any nonliteral clue automatically indicates bravery
• Because every non-courage-related lion feature necessarily supplies a fitting ground