What does it mean the scarecrow rules over thee emerald city?

In "The Wizard of Oz," the phrase "the scarecrow rules over the Emerald City" signifies the unexpected nature of leadership and wisdom. Despite being perceived as simple and lacking intelligence, the Scarecrow ultimately embodies qualities of compassion and understanding, proving that true leadership goes beyond conventional wisdom. His position as a ruler also highlights themes of self-discovery and the importance of valuing one's intrinsic worth, regardless of societal expectations.