we might not know that though. Even if we take the Emperor out of the equation. hmmmm.....then again. Guan Sui and Hong Liong is better together than GanGan.
but come to think of it.
Hong Liong is in fact the real daughter to the Minister. GanGan is the daughter of the other country.
So, when the Minister's wife said who saves her daugther I will married her to that hero. Guan Sui stepped up.
While the Emperor and the King of the other country has a wedding contract with each other. He and GanGan met is in fact fated to happened.
So, it turns out both wedding contract was in fact correct in the end.