Good examples.
And notably, the dust has not yet settled, as seasoned CV.us lurkers can attest.
I think you're blurring distinctions here.
First of all on the issue of the evolution of human society, your examples: "tan leather, make weapons like bows, arrows, flint or obsidian blades, etc." may simply represent a different portion of history.
And thus far beyond what I consider a "clan".
clan
(klăn)n.
1. A traditional social unit in the Scottish Highlands, consisting of a number of families claiming a common ancestor and following the same hereditary chieftain.
2. A division of a tribe tracing descent from a common ancestor.
3. A large group of relatives, friends, or associates.
[Middle English, from Scottish Gaelic clann, family, from Old Irish cland, offspring, from Latin planta, plant, sprout; see plat- in the Appendix of Indo-European roots.]
Word History: The word clan is, from the etymological point of view, the same word as plant. ... More at: The American Heritage® Dictionary. All rights reserved.
Splendid.
But these are things that also could have been done by small clans, or even family sized groups, or even individuals.
Division of labor hit stride when it resulted in the introduction of innovation, things that wouldn't have existed without such occupational diversification.
I don't know enough about it, but wicked candles come to mind. Difficult for me to imagine a rogue (solitary) caveman braiding fibers, and then dipping them in a cauldron of melted candle wax to complement his pterodactyl candelabra.
storm petrel
A Wick-ed Idea: Real Birds as Candles
Long before Thomas Edison, someone had another bright idea. Why not take a dead, oily bird, slip a string through its dried carcass, and use it as a candle? It worked. Up till nearly a century ago,…
awingandaway.wordpress.com