Only by uniting the cities to form a closer alliance, under one voice, and harnessing the power of all cities for oneself, is the most correct choice.
But the uniqueness of the Giant Dragon Coast means that the real decision-makers are not these City Lords and mayors on the surface, but the Dark Alliance that manipulates everything behind the scenes.
And this is precisely what the ruler behind the scenes of West Gate City, the Mask of Dark Night, dreams of doing. Naturally, he is actively promoting this matter behind the scenes, employing every conceivable means: persuasion, bribery, intimidation, threats, assassination, support, and so on. He soon garnered a group of supporters within the Dark Alliance, becoming the majority there.
Once the Dark Alliance has a unified voice, the opinions of the City Lords on the surface naturally become unified as well.