Undivided /
Planar movement, or the climbers slide off the mesa.
Walkable terrain went in. The steering quietly pulled everyone back down.
Elevated ground is an analytic height field: a plateau has a flat top and a linear skirt, and the ground height at any point is the tallest contribution. Entities snap to it, the puppets read their height from the same field, and a tagged mesh becomes climbable without a navmesh.
First test: the soldiers reached about a fifth of the mesa height and stopped. The steering was the culprit. A move target on the ground below has a lower Z than a climber, so the steering vector pointed partly downhill and fought the slope every frame. Sixty percent on the second try, still wrong.
The fix is to make movement planar: targets carry the mover's own height, vertical velocity is zeroed, and the height field owns Z outright. After that the error between soldiers and terrain was zero at the median across nearly two thousand samples on the mesa top. Rule kept for later: anything that steers should not be allowed an opinion about altitude.