Good point! Leather armor wouldn't actually do much against the sort of stuff that's starting to wake up at the valley...
I had an idea for this that might end up being cut. I wanted to have an R&D project that would produce a special sort of fabric that can only exist in the labyrinth, that's resistant against most of the environmental hazards of the valley while still being unintrusive and cool enough to allow for exploration. We'll see if we can put it in.