I had to re read the whole series with the official translation to understand haha. This is my understanding, correct me if I'm wrong.
Sandal situation:
They are one of the power houses, they live and rule the south where their economy revolves around sugar from sugarcane.
They are so powerful and influential that the emperor and the crown prince have confidants from that house. Lat and Pai ( the one with the sister).
The explorer who the empress and Lyrica support, came back with sugar root. The empress knowing the Impact of this plant made a deal with Lyrica, who actually bought it, to mass produce sugar at a lower cost. All will be produced in the north were the land is bare and people are poor. This is also where the wolve house rule.
Regretfully this caused a downfall with the Sandal house and Pai stopped going to see the crown prince.
Even worse, they were the ones who sought out Barrat to get poison and tried to kill Lyrica. Actually the brother.
Now that things have calmed due to the extermination of the responsables, they are only worried about the remaining traitors who want Lyrica as a bargaining chip.
These are the ones who are trying to capture and or kill mc. But Pai wants nothing to do with that and is infact trying to help her sister.
Spoiler: Pai's sister has the same issue as Lauv (Lyrica's guard) and in the first timeline Sandal sided with Barrat to because of this. In this timeline mc will help her.
I refuse to keep seeing them like this. I hurts! I'll stop reading until they are back together :(