As far as the distinction between an allegory and metaphor is worried, each seem to belong to the same team of figures of speech. The main reason is that both of those indicate comparison. In his book In Other Sneakers: Songs, Metaphor, Empathy, Existence Kendall Walton also sites the formulation https://manuelxcfij.bimmwiki.com/10908422/5_easy_facts_about_metafora_described