That's pretty rare considering it's hard to find any at all
~Tracer
With the thread title being "What are the odds for this?"
Because the event you are asking about did happen the awnswer is that the odds of it happening are 1:1
I'm not sure what the odds of it happening in the future will be though, my guess it will be somewhere far greater than 1:1
I have had two sets of stones spawn next to each other, but never two fruits or dung.