Why was the dream of Zhang Guanyu flying deleted in The Romance of the New Three Kingdoms?

Guan Yu and Zhang Fei of the New Three Kingdoms deleted the dream because it was strange. Based on the original Romance of the Three Kingdoms, the play tells the whole process from the tripartite confrontation at the end of the Eastern Han Dynasty, to the tripartite confrontation after the battle of Guandu and Battle of Red Cliffs, and then to the return of the world to gold after Sima Jia usurped the Wei regime. Among them, Liu Bei was dreamed by Guan Yu and Zhang Fei in Baidicheng, which highlighted brotherhood, but it was extremely strange and deleted.