Well, using umbrellas as a weapon is, you know, a real thing
. I could definitely see one of these uses for a homocide in a Nolan film.
But when it comes down to it the Penguin is a guy who dresses in a dapper fashion, and is fat and wealthy. He doesn't need to be less realistic then Brother Mouzone of The Wire
. Of the more iconic Batman villains he's one of the easier ones to stick into a 'realistic' story - far more so then the Joker, and mountains more so then the Ra's character.