Benjamin should rethink using these sources because a war scene from a movie may not accurately represent the realities of World War I, and his neighbor's great uncle may have had experiences that are not representative of the overall war effort. Instead, Benjamin could use primary source documents, such as letters, diaries, and government reports, to gain a better understanding of the war. He could also consult with expert historians to provide a more accurate and comprehensive view of the historical events.

Additionally, Benjamin could consider visiting museums or historical sites related to World War I to see artifacts and learn more about the conditions and experiences of soldiers during the war. By using a variety of reliable and credible sources, Benjamin can ensure that he is accurately representing the history of World War I in his research.