Here is a solution but it is not perfect.
Add to Sprite10 the instance variable (Overlap = 0)
If two Sprite10 overlap each other, the furthest to Sprite6 will set his overlap variable to 1.
If the overlap variable is 1, the Sprite10 stop his pathfinding, wait 0.1s then "reset" his overlap variable.
I tried with 5 instances of Sprite10 and it works, you can manage the Z position of Sprite10 in the layer for better results.