While there has never been a rule against realism in animation, and countless examples exist of the two making excellent storytelling companions, deviation from reality has always been the medium's greatest edge and appeal to young viewers. Yet, while it's accepted and expected that cartoons were never meant to make sense, the degree to which they don't is usually the first thing an adult will notice that a kid probably won't.
DuckTales is pretty middle-of-the-road weird, especially alongside such contemporaries as Gargoyles, Teenage Mutant Ninja Turtles, and Biker Mice from Mars. Scrooge and his anthropomorphized companions are neither mutants nor space aliens, and for the most part the show's fantasticality usually stays within Scooby-Doo territory (though the ghosts are usually real). Sure, the adventures are improbable, and the characters less killable than a Volvo 240, but that's just the anatomy of an adventure story. Yet, if one tried to pass the same concept off using human characters, there would be one glaring quirk that flies under the radar in the cartoon: the thrill-seeking, crime-fighting, death-defying central character is none other than Ebenezer Scrooge (albeit in duck form), central character to Charles Dickens' A Christmas Carol.
Tracing Scrooge's history from literature's worst boss to beloved cartoon duck makes the leap a little less extreme, but even contextualized, the premise reads a little like a sequel to Abraham Lincoln: Vampire Hunter. Perhaps it's a testament to Scrooge as one of the original memes that this bizarre casting flies by without much thought.