I've read a few of the Wimsey stories. His character, as fleshed out in the introductory sections, is more complex than first appears. The result of his grandfathers' efforts to improve the families' inbred genetics, Wimsey has an intelligent but slightly neurotic French mother, So that while his elder brother, the Duke, is a 'beef-witted English Squire', Wimsey takes after his mother and is 'all nerves and nose'. His cleverness makes him an anomaly among the British aristocracy, who don't breed for brains, but for utter fearlessness and the ability to stick on a horse as if born in the saddle. Add to this he suffers from 'shell-shock' (PTSD) from service in the Great War and is, of course, not permitted to even consider gainful employment, and you have a picture of a man at once at ease and out of place in the society he must live in. The sleuthing, as well as the book-collecting, are his ways of making his life productive, rather than simply being a playboy.

His way of talking was the way the aristocracy talked back then and has its' roots in Regency times, Public School slang and Victorian 'small talk'.

I confess to writing a fanfiction that featured Lord Peter. Set in the 20s and teaming the aristocratic sleuth with Indiana Jones in the search for the dread Claw of Cthulhu!

That said, the books are average at best, but marginally less contrived than Agatha Christie - with whom I have no patience - the Enid Blyton of detective fiction.

Also, IMO, to call Poe one of the greats of detective fiction on the strength of two short stories is a little much!