Generally speaking, this order is parallel, and it is also the easiest for readers to think that it is parallel. We use this sort to basically use parallel text.

However, there is no definite method for writing. Some articles with obvious logical relationship and distinct arguments will use the first, second and third, but the relationship between them is hierarchical.

If the purpose of asking this question is to write your own article, then both juxtaposition and progression can be applied. Progressive writing, on the other hand, is more difficult, requiring higher logical relations between contents and writing processing. Parallel is relatively simple, just cut into pieces and typeset. If the purpose is to understand the article, then this formal thing cannot be used as a conclusion to the content. And in fact, many people's articles are often arbitrary, rarely strictly follow the rules of grammar and logic, but they are reasonable.

Therefore, the key is content, not form. There is no point in obsessing about form. Of course, before you become everyone or you don't have a certain quality, the necessary form is still essential.