Bip39 vs electrum https://pastelink.net/caobqzis A BIP39 seed phrase created with proper randomness can't be guessed via brute force, due to the fact you'll find just too many permutations. Because of the cryptographic style and design of BIP-39, a weak passphrase isn't going to reduce the protection of the other wallets https://squareblogs.net/edelinepge/using-python-to-produce-a-bip39-mnemonic-a-developers-point-of-view