I gave this a quick shot and failed as well. What I can say is that using invisible helper sprites as pinning assistants didn't work out in the end, and if I were to attempt again I would definitely utilize families, probably not rely on the built in behaviors, and use an instance variable to keep track of groups of pinned objects.
The good news is that the pin and drag drop behavior are both probably among the easiest ones to recreate by events.
Scene graph hierarchies may also possibly be of use here to keep track of groups, but I unfortunately have zero experience with those yet so I'm not sure.
Thanks for trying,
You seem to be right after trying for hours I'm almost about to conclude that pin behavior isn't able to do this and drag&drop is very plain. Going to try to do it with heavy logic if there is no simple solution from no one.
That heavy logic would be:
If SpriteX offsetX < 30.
-> SpriteX(1).X = SpriteX(1).X - 30 (bring them closer)
-> Save in some storage(json)
-> -> SpriteX(0) parent of SpriteX(1)
On dragging
-> If has child move child to parent position.
Praying for easier solution from someone before i start my conquest of try&error. :D
Again thanks for trying!