I've noticed that when deconstructing a machining table in 1.1 I sometimes get 3 components back, sometimes 4. I'm poking around a bit to understand this better. Current pointers.
Deconstructing a structure returns 75% of the original resource cost. Expect the cost to average out to 3.75 components over time, albeit every time it is rounded to either 3 or 4.
That's what it looks like reading the code (with the call to GenMath.RoundRandom and all), but I just tried building ~20 electric smithys in 1.1 and then deconstructing. Every single time I got back exactly two components. Same for an electric stove -- it seems to always return one component. It's only the machining table that would actually seem to return a variable # of resources for me.