Besides that i doubt that such a chain 'Pin A to B & pin B to C' actual will work Pin Wise ....
Making that chain is easy ....
System > For > name = "i" .. start = zero ... end is Sprite1.count - 1
System > Pick nth instance > object = Sprite1.. Instance = loopindex("i")
System > Pick nth instance > object = Sprite2.. Instance = loopindex("i")
System > Pick nth instance > object = Sprite3.. Instance = loopindex("i")
______________actions > Pin Sprite1 to Sprite2
______________actions > Pin Sprite2 to Sprite3