A structurally forceful expression is not always best for every purpose. In testimony or teaching, the limitation “in courage” may provide exactly the clarity required of the audience.
In a context of literary praise, “Zayd is a lion” may create a more intense impression. The speaker's choice depends on the communicative purpose and the hearer's situation.
Distinguishing intensity of overstatement from appropriateness of expression prevents a common mistake: the strongest grammatical form need not be the best utterance if it fails the task it was intended to perform.