ANZAC day is not really remembered very well in the UK but we do owe them one hell of a lot!
It is a never ending question about lubricating the linkage balls. In a soil engaging operation it is better to have them dry especially if the lower links are close to dusty soil (quite rare in the UK) where they can and will pick up grit.
For less gritty jobs or where non-abrasive dust may be present I would be inclined to keep a very light lubrication present. A small squirt from an oil can would be enough to help a little but not provide a build-up of say grease which would hold grit. Likewise for the front lower balls.
I can't find any MF guidance on this so I guess it is down to everyones own choice.