Even having fallen far from grace and already split into different groups, the Song family etching its survival on the hinterlands bordering the Deer Mountain Range to the north still had the reserves that one would expect of a former ruling clan of a rank 2 empire. They had two palace realm experts in their midst, and a few treasures and trump cards that gave them enough bargaining power against the four families i.e. the Zhou family, the Chu Family, the Meng Family, and the Shi family.
The four families each had at least one palace realm expert with the Zhou family having three, counting the Zhang clan's founder, who was their retainer at the time. Despite having more cultivators than the Song family, the four chose to ally with them rather than try and dominate them, owing to the family's capabilities.