Great video, clearly described everything, helpful. Anyway one thing is not clear to me. In chart 2, the scale distance between units in x axis has changed , and before overlapping you did the no fill for x values in chart 2. So, after overlapping if the x axis value of chart 2 uses the x value from chart 1, it would give the wrong or inappropriate value. Even, in paint you calculate value and put there to prove this. For visualization it is good, but for real interpretation it would be difficult.