The military use of the sling depended on shepherds. A shepherd has plenty of free time, broken only by the need for dealing with idiot sheep. He could spend hours every day practicing with a sling. This was good because wolves like sheep a lot. When a wolf pack shows up, looking for dinner, it’s a really good thing to be able to kill a few at a distance. Wolves aren’t stupid. When they are killed from beyond attack range, they look for an easier meal. That’s why shepherds whiled away the idol hour slinging stones at innocent targets.

When Saul or Cyrus or Alexander or Caesar wanted military slingers, they started by recruiting shepherds.