The organization of a paper matters at the level of the whole essay as well as within each paragraph. The organization of sentences matters within paragraphs, as writers choose which sentences to put in what order and how to create a smooth sense of connection between each sentence. But organization also matters between paragraphs, as writers choose when to present their ideas to their readers for the best effect.
The organization of texts is based upon conventions of particular genres. The ways in which texts are organized, are structured, and flow is determined largely by audience expectations.