With the same number of zones and passages, I increased the minimum number of steps from 6 to 8:
In my version, from any player to any treasure on the map, there are 3-5 steps; in yours, to the nearest treasures, there are 3 steps, to the farthest ones, 6-9 steps, meaning the treasures are effectively divided into "ours" and "theirs," which is exactly what I'm trying to avoid.