If a book series is written as a trilogy, you'd be correct. Most trilogies suffer from a "1 + 2" problem where the first book holds up but book two and three are two halves of a continued story. Its one of my pet peeves. But LotR was written to be one singular book. The publisher decided to trilogize it. So I give Tolkien a pass. He intended for you to read it in one go.