Hegel, Nietzsche, Wittgenstein, and Anscombe all write mostly in numbered paragraphs. (Of course Hegel and Nietzsche have chapters. And many of Hegel's lectures aren't written in this way, but both Logics, PR and PS are.)
To some extent this makes sense for Nietzsche---aphorisms are supposed to stand on their own, yet exist in context. But the Genealogy is not a collection of aphorisms and could easily have been written in a continuous flow. And I think the same is true of Hegel.
I could guess that early Wittgenstein was following Russel in writing this way. Perhaps each statement in the Tractatus is supposed to stand alone uncontroversially, like a theorem. But he keeps the form up all the way through his life, and Anscombe copies it in Intention.
Have any of them ever explained this strange organization? Who has written on why these thinkers thought it necessary to write in this form?