I wonder why mash-ups with Austen have become so popular? As attested to in this article in The Independent. I don't believe it's simply the incongruity.
But it's nothing new. Terry Pratchett tells us that when he was thirteen: "I wrote a crossover short story, Jane Austen meets J.R.R. Tolkien. It was great, especially the bit where the orcs attack the rectory.”