Origins of the first empress, Duan Qui

While Gong Jie may have not known much about their founder, Deng Wei, or his deep friendship with their ancestor, he did know enough about the royal family and the troubles that were brewing within. All the top figures within the six founding families did. It was why some, like the Mo family, were emboldened enough to try and whittle down their power as they made an attempt for the crown.

The Duan royal family was split and while the core reason for that had to do with the Zou family, the Zou family coming into the picture served more of an impetus for that split more than anything else. 

The royal family was currently split into two factions and the reason for that split had to do with their ancestry.