Hey so I really liked your solution. For me the simpler, the better.
I was having trouble understanding why you needed the sampling tool? But I also noticed when I tried to run the workflow without it, the workflow was taking forveverrr to run. Does the sampling tool limit the data size? If so, does it apply the tools after it, to only the sample data or to it all.
I guess I need to learn about the tool itself. xD
Thanks for sharing!