Hello Umberto,
thanks for considering my proposal. I actually had something much more humble in mind: the passengers don't need to remain in the airplane. However, GSX could keep track on which passenger figures have boarded and then, during deboarding, use the same figures. You probably have a number assigned to each figure (say, 1=old man, 2= old woman, 3=boy, ..) and then randomly select them during boarding (say, 1,1,3,2). GSX could save that information and then use 1,1,3,2 (or a permutation of it) during deboarding.
Best regards,
Peter