My answer may not be accurate enough. According to my knowledge, the Four Zombie Kings refer to the four famous zombie film directors in the Hong Kong film industry. They are Wong Wai Man, lam Ching Ying, Hui Guan Man, and Mak Tai Xiong. Their works had different styles, but they were all based on zombies and were very popular with the audience. Huang Weiwen's works were mainly horror and thrill-based, and his more famous movies included Mr. Zombie, The Exorcist, and The Zombie Family. His works were even more hilarious and nonsensical. His famous movies included Zombie Supremacy, Death Game, and Mr. Zombie 2. Xu Guanwen's works were more focused on the plot and character creation. Among them, the more famous movies included Zombie Uncle, Hong Xiguan, and Zombie World War. Mak Dang Xiong's works were mainly horror and thrill-based. His more famous movies included Mr. Zombie 3, New Human Zombies, and Uncle Zombie. Although these directors 'works were mainly about zombies, their works had different styles and types. Therefore, it could be said that some movies might be called one of the four zombie kings, but whether they were included or not depended on the specific movie.