When you create a family object, a random member of the family is created. So you need to specify which object you want to create.
Do this:
Note that DragDrop behavior is enabled by default for all parts.
Another option is to add an instance variable "type" to the Parts family and do something like this:
Parts on GragDrop Start
...Parts type=24 -> Parts spawn Attack24
...Parts type=26 -> Parts spawn Attack26
...
...