A little clarification might help here:
Automatic ballons do NOT change the number if re-attached.
Manual ballons change the number if re-attached. ( on update partslist)
I have found no option to highligt the difference on which ballon is automatic / manual.
Note, that if you RMB the partslist ( instead of the view) you can select multiple views for NX to create the ballons in, it usually helps on the question where leaders get attached to almost invisible objects, or ballons missing.
Regards,
Tomas