Good question, good topic for discussion.
I think the basic idea is that in hunter-gatherer/nomadic pastoralist societies, everyone is working every day doing the normal chores required to maintain the group. While most info points to hunter/gatherer bands having on average more free time than urban folk, the lifestyle generally doesn't create a surplus of food.
Once you get settled, agricultural groups, you start to get food surpluses that allow specialized non-food gathering people to exist, such as a distinct warrior class, a distinct priest class, and dedicated artists.
So by that idea, yes you'd need urbanization to allow for specialized craftsman such as bladesmiths.
So does it always play out like this?
Generally, I think so. Tibetan herders in the past handful of centuries rode on elaborately decorated saddles and carried knives made by "Sino-Tibetan" craftsman from the cities, who often enough were Chinese.
Are Dyak and Moro groups exceptions? I'd expect wide variation between the groups and sub-groups, but did they generally stick around to one place or as tribes move around a lot?
Anyway, my two cents
