That guide shouldn't be followed since it's not the correct way to set-up a MultiSig Electrum wallet using hardware devices.

The users don't need to create a standard wallet in order to get the hardware wallet's xpubs (master public key).
During the creation process, each cosigners should start creating a MultiSig wallet right from the start until the point when they'll be presented with their "Master Public Key".
Then send it to other cosigners (as that cosigner receive theirs) to finish their own MultiSig wallets.