There are so many other risk assessment techniques out there, for reference ISO31010 lists 30 of them (see here) and they’re far from exhaustive.
Almost nothing on the list you’ve linked is an alternative approach to the same problem safety cases try to solve. E.g. “brainstorming” is obviously not a competitor to safety cases. And safety cases are not even an item in that list!
@Ryan Greenblatt and I are going to record another podcast together (see the previous one here). We’d love to hear topics that you’d like us to discuss. (The questions people proposed last time are here, for reference.) We’re most likely to discuss issues related to AI, but a broad set of topics other than “preventing AI takeover” are on topic. E.g. last time we talked about the cost to the far future of humans making bad decisions about what to do with AI, and the risk of galactic scale wild animal suffering.