I dont believe there is a way to force a refresh in the way you are looking for.
It has always been a case of "whoever selects OK last wins"
You do find that recent versions, especially with policies etc. do warn a user that other changes have already been made and that their changes are not valid so that the user has to reload and make the changes again.
However, the only real way to keep this under control is for any changes you need to make to go through change control (even if a very simple change control where changes are registered first and the person allocated to do that change allocated - a simple spreadsheet would be fine)
Hope this helps - "too many cooks" and all that!
