He's also significantly more difficult to hit than the person pulling the sling is themselves. A sling can roll over, and up in front of the payload, and shoot it backwards, but it will only hit someone in the Y-holder's position if the pullback is very weak.
Of course, if the payload is a grenade, it doesn't matter a whole lot which one is hit first.
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|...............| We live in the nick of times.
| Len 17, Wid 3 |
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