[GRRM is asked about the section numbering scheme for his novella, "The Meathouse Man"
That's a good question, and a hard one. It's been a couple of decades since I wrote that story. I had a profound and artistic reason for the numerbering, I recall, but just what it was...
One obvious difference, however, is that all the Arabic numerals reference song titles, and the content of those sections were in part inspired by those songs, or alluded to said content. The Roman numeral section titles are simply descriptive.