Well, it's not strictly necessary. The anime might give you a decent overview. But the manga often has more details and might offer a different perspective.
" White Deer Plain " was a classic of modern Chinese literature. The movie " White Deer Plain " was adapted from the novel and faithfully presented the plot and characters in the novel. After watching the movie and the novel, the readers might have different feelings and understandings.
Compared to the movie, the novel presented the characters, story plot, and historical background in a more in-depth manner, allowing the readers to feel the atmosphere and emotions in the novel in a more detailed manner. Therefore, if you are interested in the characters and plots in the novel or want to have a deeper understanding of China's history and culture, reading novels is a better choice.
Although the movie White Deer Plain also faithfully presented the plot and characters in the novel, its time limit and the way the images were presented might make some readers feel visual fatigue or unable to fully immerse themselves in the novel. Therefore, if you were mainly interested in the plot and characters in the novel or just wanted to watch an excellent movie, you could choose to watch a movie.
Reading novels and watching movies have their own advantages and limitations. You can make a choice according to your own interests and needs.