chieftain
酋 centers on a leader of a group, specifically a chieftain or tribal chief.
酋 is thought to depict a container of wine (酉) with a distinguishing mark (丷) on top, representing a leader who distributes or presides over ritual wine. The exact historical development is uncertain, but the association with a chieftain is well established.
The top 丷 looks like a chief's headdress or horns, and the bottom 酉 is a wine vessel. Picture a chieftain wearing a ceremonial headdress, holding a wine jar to lead a feast.
For シュウ, imagine the chieftain giving a loud 'shoo!' to gather the tribe: shoo -> シュウ, and the chief leads everyone together.