One fun thing about the Discworld fandom is the way they've created these extremely detailed and evolving reading order documents that track all the different sub-series of Discworld to help guide peoples reading experience (starting with The Colour of Magic and going in chronological order is probably not going to be the best experience. Most of them are standalone enough that you can probably just start reading with whatever book happens to look most interesting to you, then you can use one of the aforementioned guides to find the books in the series that are most like it in terms of characters and themes.) I hope someone has done a paper that's just them compiling a bunch of these to see how they've evolved and if there are any taxonomic ambiguities.