well, the short answer is that the book is entirely, entirely a different animal than the movies. in addition, the book “The Hobbit” is also a rather different animal to the rest of the legendarium.
omg, they wanted to give Dwalin an animal theme for his character design and the decorations he has, like a ram or a fox, but they didn’t (eeeee). also PJ said it’s too much for them to drag around their canon instruments (truly) so only Dwalin kept his fiddle and the one who designed it had a son with a degree in early music so I think Dwalin’s fiddle is fairly accurate based on that???? *clings to the books and refuses to leave*