What PC class should a well-designed ruler have?

[Yahzi Coyote]

Nitpick: The area affected by a single casting of Plant Growth is about 0.7854 square miles, which is about 502.7 acres.

If he only casts during one season (100 days), that's still farmland for 12,500 people.

But apparently the setting already has a bunch of casters to do this.