A bit confused with the example. If the family is gonna contain different sprites (objects), then 'is sprite over overlapping family' is a bit weird (in my eyes). If the family gonna contain instances of the same sprite, then use 'is sprite overlapping sprite'. Pick nth will work flawless, pickedcount will work flawless also.
In the other case, if the family gonna contain different sprites, then make a second family. And use 'is family1 overlapping family2'. This works if both familys contain exactly the same objects. Only under those circumstances IID will make some sense. Pick nth will work flawless, pickedcount will work flawless also.
I never uses 'is family1 overlapping family1'. You might try.
The solution is in the link i suggested you to read, btw.