Maybe I wasn't clear enough. I am pointing out that the low entropy of a seed and extending a low entropy seed with a strong 13th word is not a substitute. So, I was saying it's better to pick random seeds created using the tools designed for it instead of picking on our own since we are prone to making choices that are easy for the computer to crack.
BTW, thanks for the link.
Yes, security is never too much, this was just an example of how a passphrase makes a big difference to security.BTW, thanks for the link.
It's not that I'm recommending creating a low-entropy seed with repeated words, for example: "bacon bacon bacon (12x)" and compensating the security with a strong passphrase.
However, a wallet protected by a passphrase is a new wallet (new set of keys) compared to a wallet with an empty passphrase, so if I create a wallet with a 128-bit passphrase, I would generate a new wallet with 128 bits of entropy.