Background: read Slaughterhouse 5 first as it seems to be a favorite on reddit, was not blown away, but interested. Next, Cat's Cradle, the storytelling and characters alone were enough to make me finish it in a day, may be my favorite book of all time. Now I'm 100 pages into Mother Night and just discovered/remembered Howard Campbell's small part in Slaughterhouse Five where he is described similarly organizing the 'Free American Corps', but (potential spoiler) is married to 'Resi North' vice 'Helga Noth' as in Mother Night. The nickname/character Blue Fairy Godmother is also reused between this two books at least. My concern is that these seem like very subtle, side characters in one book, and major characters (specifically Campbell) in another. Should Vonnegut's works be read in the chronological order of their publish date, are all of the small character going to be major one's in other books? How did reddit recognize/handle these character overlaps?