I have attached a workbook with two samples from a series of daily charts I'm preparing.  I want the legend entry for the series with the greatest value to be on top.

In the chart on the left, M2 is greater than M1, but the legend entries show M1 on top (as it's the first series charted).

In the chart on the right, M1 is greater than M2, and the legend shows M1 on top, as I want.

I know that I can manually fix the chart on the left by changing the sequence of the series, but I need a way to have this happen automatically, as some days will have M2>M1, and others will have M1>M2.