The word "poetry" is now generally used as if it referred to lyric poetry, a kind of writing that is not prose or prosaic. What is written in prose is always capable of being written in words other than the words used. But when something is written poetically, the words used are the only words adequate for expressing the writer's intent.
The opposition between verse and prose, or between poetical and prosaic writing, is not relevant to what the word "poetry" meant in ancient and medieval times, and meant in modern times until the nineteenth century. Poetry was then understood to stand for all imaginative literature, for all narrative fiction -- for novels and dramas, all words of the intellectual imagination.
Aristotle tells us in his Poetics that poetry is more philosophical than history, because historical narratives deal with singular past events, whereas poetical narratives deal with possible generalities. The characters in imaginative literature are types of human nature. This is unaffected by the style of writing, whether in verse or prose.
Another saying worth remembering here is that history is often stranger than fiction. What actually did happen in the past is less intelligible to us than what might have happened.
Finally, we must consider the distinction between poetical and logical truth. When we think that something is logically true, we must also think that what is contrary or contradictory to the proposition we judge to be true must be false. Logical truth is exclusionary. Not so for what is only poetically true, for here we are dealing with narratives that have verisimilitude -- acceptable to us because they are likely to be true.
Poetical truth is not exclusionary. For example, among the Greek tragedies there can be many stores about Clytemnestra and Electra, all different but all poetically true.