In the rather distant past was DeskBabes (now set c, called IStripper Classic collection).
During much of this time (not all), four girls got together, where each girl did a solo and one duo with each of the other three.
Example 1
Niki Sweet, Lucy Bell, Iris, Gettin Cute
   - Niki Sweet and Lucy Bell
 - Niki Sweet and Iris
 - Niki Sweet and Gettin Cute
 - Lucy Bell and Iris
 - Lucy Bell and Gettin Cute
 - Iris and Gettin Cute
 
Example 2
Victoria Blaze, Leila Smith, Ferrara Gomez, Samantha Jolie
   - Victoria Blaze and Leila Smith
 - Victoria Blaze and Ferrara Gomez
 - Victoria Blaze and Samantha Jolie
 - Leila Smith and Ferrara Gomez
 - Leila Smith and Samantha Jolie
 - Ferrara Gomez and Samantha Jolie
 
By the way, I own all twenty cards of all these girls.
Lots of other girls were like this. I own all ten cards of each of twenty-four others like this. (lots of cards)
My questions:
How was this possible back then and not now or since the e and f cards began?
What made it possible for each girl to do a solo and three duos?
Why does this no longer happen and has not happened for many years?
What can be done to make it happen again, if anything?