You can see the other side of the "sheepherder kills elite pre-Greek warrior" story in the Argonautica book 4 verse 1485-1500:

> On pasturing flocks didst thou light; and there followed a shepherd who, in defence of his own sheep, while thou weft leading them off to thy comrades in their need, slew thee by the cast of a stone

In this story it's in the desert of North Africa vs Palestine and isn't a dual.

But either (a) sheepherders were killing elite pre-Greek warriors regularly with the cast of a stone, (b) one story influenced the other's existence while somehow having little to no other shared details or attribution, or (c) an event like that may have actually occurred and left a lasting impression on both sides, which over time morphed into their respective versions in each group identity, woven into broader events.