There's also that Peter Jackson's movies botch (intentionally, for dramatic purposes) some things that are present in the books.

For example, the city of Gondor seems like a giant fortress without any fields or farmers working outside its walls to sustain it. This even before any siege. So what do they eat?

Tolkien wouldn't have made this mistake, it's likely Jackson's. And I understand why: people want to see epic battles, farmers doing their thing are a low cinematic priority.