But in general, I agree that the first lines of defense are the most important, especially the ones preventing a personal conflict altogether. Because those can end up messy.
- Opsec: Don't let people know you own valuable stuff.
- Physical security: Make sure people cannot easily enter your property in general.
- Plausible deniability: Have decoy wallets / other measures that make a thief believe they 'got everything'.
- Self defense: If everything else fails, e.g. they keep asking for more or keep applying violence, have some backup plan.
- Passphrases / Multisig: Have your main stash either stored in a very hidden location or use passphrases and multisig. For instance, every one of the stolen (funded) wallets could be restored from a backup, which - appending a 13th / 25th word - creates a whole new wallet with the actual funds. Alternatively, have wallets in a completely different location that are required to complete a multisig wallet with the real funds. Of course, also have backups of every wallet in other locations.
Honorable mention: data can at times be as or even more valuable than money. Keep your (encrypted) backups updated! And of course encrypt your hard drives. I imagine a thief may want to just take stuff like portable computers with them and figure out how to extract wallets, later.