I prefer the figure of speech: “jack of all trades, master of one”.

If you think about Da Vinci, this applied to him. He was a master artist, and this enabled his success (or at least his grandure of thought) in the other areas in which he dabbled. He was able to crystalise his ideas on paper in a way that few others could. In this way, I would argue that he had developed a means of innate focus, allowing him to be unfocussed with precision.