I'm not sure that using SAN in a traditional fantasy setting is really an issue. Humans, Dwarves, Elves, and the like are pretty close to one another, not much of a shock at all. Orcs/Trolls, etc, might provoke a small loss, if they are particularly ferocious. A Lich or a feeding Ghoul more so. Demons and Mythos creatures even more. It can work well to convey horror even in a fantasy setting, you just have to determine how different the creatures really are from the baseline.
In Glorantha for instance, because the base races are so different, I can see a human needing to make a roll if they see an Aldryami drop from its pod, or a Mostali lifted from the vat full grown... etc.
SDLeary