Thanks a lot for the lovely feedback about the Remi award; since ever I do anything with the people here on the forum in mind when I create. It evidently works to have a great audience :-), and be part of a great team!
Here I use a "cage" as a proxy/dummy object, which could be even more simplified. With this, any shoe inside the cage (or close to the surface) will stay as it is, how twisted you might go in the future with a model.
This looks to me like a 4x4 matrix. In other words, one would create combinations that result in a square of one or the same size as a package of a few. Those packages are then set as Child Objects under a Cloner with a Random distribution. Different S.Y [scale], or 90º rotational increments for each 4x4, will increase the variety.