I don't think it's rare, but when the subject came up recently on another thread I checked my trees to see if any of them had doubles. There weren't many--one or two occurrences (or none) per tree, except for the tree on which this air layer was still attached, and for which two figs per node seems to be the norm--or at least very common. I was curious to know whether the neighbor's tree from which I took the original cutting showed the same tendency, so I went over yesterday and checked, and it does. No big deal, but kind of fun.