Questions about Alternate Worldline Design.

[Rowan]

So, I've been tinkering around with a Farther Alternate worldline in and around 883 AD. I'm tossing around the idea of a TL 3 world, but with a much lower instance of metals. Mostly, I'm looking for the worldline to be forced to adopt materials like stone and obsidian for warfare, and perhaps bronze and brass for things like coinage or maybe general use materials? I'm not sure how viable the idea is. specifically what I'm wondering is, how plausible would it be to have a farther alternate worldline with most of the metals missing? Basically I'm looking to wipe out use of iron, steel, adoption of silver, gold. Basically most metals besides say metals used to make the aforementioned alloy metals.

Is this plan viable? am I barking up the wrong tree, and have I missed any potential problems by making most of the metals on this worldline absent or in such low quantities that they're not reachable?