First of all, the queen has supreme power. In TV series, it is often seen that the concubine provokes the queen because of her favor. The queen is afraid to say anything because of the king's favor, but this scene will never appear in the real historical harem. As the head of the harem, the queen has absolute authority, the king is in charge of power, and the queen is in charge of all affairs of the harem. And the queen will not be abolished because of a small mistake. The queen is not only the wife of the king, but also the mother of a country. She was elected by the ministers of the DPRK through consultation, so the position of the queen is very stable.
Second, the harem management is strict. The management of the harem in past dynasties was very strict. Concubines have separate courtyards. Except for visiting the Queen's palace every morning, they spend most of their time in their own yard, and no one will wander around at will. Moreover, the women who can enter the harem are all selected by thousands, and most of them are educated. Without those dark minds, the overall quality is still very high.
Third, it is not easy for concubines to be promoted. In TV dramas, there are often such plots. A concubine said something that made the king happy or did something, and the king immediately promoted her position. In fact, it is very difficult for a concubine to get a promotion in history. There are very strict rules for the promotion of concubines in the whole harem. Generally, concubines give birth to children and leave them to the royal family. The king will be promoted to a new position for the future growth of the prince.