If I'm not mistaken, that command changes the non-sysdba sys password for all the instances of that database. The orapwd command does one instance at a time as they have their own password file.
Wrong. "orapwd" creates the password file with reserved number of entries and put there sys password. Having other sysdba users in password file will require to you to do ALTER USER ... IDENTIFIED BY ...; So Fairlie was actually correct.
-- Best regards, Alex Gorbachev