In a scene that takes place on flat ground, the eye level (EL) usually intersects everything at about five feet above the ground. That’s because most of us of average standing height look out at the world from that elevation, and most photos are taken from that height as well. You can imply that the viewer is seated or that the viewer is a child by placing your eye level at a lower height.
Since the eye level line cuts through every figure at the same relative point, you can sort of “hang” the figures on the eye level line, just making sure the line runs through everyone at the same height. In the throne room scene here, for instance, the EL is exactly at the height of the top of the dais, or platform. If you carry that line across the scene, it will intersect every standing figure just below the shoulder.
I could have chosen to place the EL at ankle height, but then it would have intersected every figure at the ankle.
On this drawing, by the way, the vanishing point for the edges of all the carpets is just visible on the shoulder of the figure standing just to the left of the leftmost lion.
The drawing above was not drawn as a separate charcoal comprehensive. It is a pencil drawing made directly on the illustration board prior to painting. What you're looking at is a photocopy of that early stage of the painting, with the EL accentuated.