I have heard that when Sir John and king George V met, that they had a conversation in high German, the comment was I hope the troops didn't hear them doing that. I have also heard that American troops that had served under General Sir John Monash, didn't want to go back and serve under their own commanders because he was such a good commander, and that some of the American troops unofficially attached themselves to Australian units, to keep serving under Sir John Monash.
When my grandfather was a child he was a neighbour of Sir John Monash. That was before Sir John Monash got famous.