Is there a translation problem or was it originally this messy? The story of general Guo's family seems to suggest that the general originally lived in Yecheng but that the capital his wife lived in later was named Kaifeng, but the eight treasures story suggests that the princess lived originally in a palace in Jinling then was sent to Tingzhou, where she received news that her brother had lost the throne and that a new government had been established at Jiangning.
The first story clearly references the murder of Guo Wei's family by order of Liu Chengyou, the last emperor of the Later Han Dynasty when Guo was stationed in Yecheng in 950. In retaliation Guo marched against the Later Han capital of Bian and destroyed the dynasty, founding the Later Zhou Dynasty in 951. What causes confusion is that the capital is named Kaifeng in this story, whereas the name had fallen out of use long before this and its name at the time should have been just Bian. Either the author wrote anachronistically or the translator directly converted Bian to Kaifeng. Either way, the use of the name Kaifeng really confused the placement of this story in history for me because it seemed like the story took place in the Ming Dynasty.
The second story seems to indicate that it happened after the end of the Southern Tang kingdom in 975, when Li Yu (the brother?) the last king of Southern Tang was defeated by the armies of the Song Dynasty and taken in captivity to the Song capital Bianliang (later Bianjing). His former capital of Jinling was then renamed Jiangning by the Song. What makes this story confusing is the offhand remark at the start that a general Guo had started serving the emperor, which immediately calls to mind the general Guo of the first chapter, but his emperor was already dead according to his wife. I take it this is another general Guo formerly of Southern Tang who chose to serve the Song emperor. Additionally, the letter received by (former) Princess Yushan is very confusing because the translation talks about a Yecheng, this time a person, who tried to impose himself as emperor and that her brother was forced to abdicate as a result. Nothing like this happened in history. Li Yu was poisoned by Song Taizong in 977 for writing a poetry lamenting his fate and the rape of his wife by the emperor.