Thank you for presenting me with such a valuable, visual expression. I didn’t know it but it applies to this sit X2.
I also tried to remember my school days combinatorics maths concepts of variations, combinations and permutations. The possibilities were nearly unlimited with 5 cats coming and going, returning (or not) and changing their minds 
It will certainly come handy if an HO asks me to do that in the future.
Herding cats is an idiom for attempting to control or organize a chaotic, unruly, or inherently independent group, making a task seem impossible.