Bip39. Thanks to the cryptographic style of BIP-39, a weak passphrase will not lessen the security of the opposite wallets or enable expose the seed words. Mnemonics are representation of entropy. Starting point includes generating a decision as to exactly how much entropy you think about Secure for the operations. https://bookmarktiger.com/story19078769/bip39-list-https-linktr-ee-bip39-5-easy-facts-about-bip39-generator-described