The levels worked out better this way anyway.
The other lines on the chart are internal pointer angles. Often there are internal angles that can assist in the external angle setting. Levels are similar to that. These are really that are repeating
Once the highest high and the lowest low have been established this method works best. Also if you have a shallow baseline angle along the lowest bottoms or the tops, this idea works better then. The pointer aren't always the lowest low or highest high. They just give an angle that will be used again.