This is kind of needlessly overcomplicated, and could potentially discourage potential new readers to the point where they'll just give up and not read anything.
The books are fine if you just read them in publishing order. Which basically every book has printed in it for reference. It works just fine that way (and arguably, it's better than trying to construct complicated counter-intuitive orders for them). People always try to make the order of larger series more complicated than it needs to be.
It's why I always get a bit annoyed when people suggest things like reading the Narnia books or watching the Star Wars movies in chronological order rather than publishing order. They weren't originally designed for that, and I think you absolutely lose some of the nuance when you do it that way. Just read/watch in the order they came out and everything is fine.
For Discworld, it's easiest just to tell people to read the books in order, and maybe skip ahead a bit if they don't like Rincewind or the parody tone of the early books (specifically, I usually suggest to anyone who doesn't like The Colour of Magic to skip ahead to Wyrd Sisters or Guards! Guards! instead. Mostly just Guards! Guards!, because I think the City Watch books are easily the strongest in the series). The book list on Wikipedia is perfectly acceptable for that purpose - it lists every book in order, and even tells you who the lead characters are so you can decide if you want to skip a given book:
I'm not disagreeing with you at all, but I do have the feeling that Ent is the best resource on the subject, hence my summoning. I'm pretty sure Entity has literally read them all so I'm just going with what I regard as the final word on the subject.
Personally, I don't really think Pratchett was trying to take the piss on the whole fantasy thing anywhere near as hard as Jim Baker was trying to because despite Pratchett dying and all, nobody is crying about any possible unfinished novels, whereas Jim is very much alive and well and holding back on the very much hyped Post Apocalypse Trilogy which might only be behind the next JRRM novel in terms of anticipation... Pratchett never managed to back himself into a corner, and at.least JRRM has left clues and DOS disks should he die abruptly. The thing that worries me most about the Dresden files novels is that in the event of an unforseen car crash we may end up with the sort of thing Doug Adams kids have hacked together post mortem.
At least Pratchett had an unreasonably large canon by the time he'd passed... ---