[whswhs]

The discussion here seems to have evolved from "how do I handle high-TL skills for characters who are being banestormed into a low-tech world?" to "how do I stop characters who are being banestormed into a low-tech world from being built with improbable expertise in archaic skills?" That's a different issue.

I think the answer requires looking at fiction about such characters. In the Nantucket trilogy, for example, a lot of the main characters turn out to have unexpectedly useful skills/advantages, from advanced training in kendo to speaking Lithuanian. But that's because they're the protagonists! There are people who don't have specially relevant skills, who get walk-on scenes; there are even people who can't adapt and commit suicide or get killed—the Lisketters, for example. But they're not the ones we spend most of our time reading about. In the same way, we don't usually want to read about the castaway who starves to death and leaves behind only his bleached bones.

So I think it's fair to allow players to design characters who have some useful skills and a background that justifies them, even if that background is improbable. (After all, nothing in their background is likely to be as improbable as being banestormed!) And I would tell my players that their characters were going to end up in another world. Of course I'd review their character sheets and question them if they came up with something that looked really abusive, just as I would players in ANY campaign. But I would tend to allow them to be a bit improbably prepared to take up their new lives; characters unexpectedly having useful skills is one of the tropes of this genre, isn't it?