How about something like

Prayer-circles

Mages stand in specific position and call forth greater magic than they would be able to alone. Think of the Tarutarus in the opening FFXI cutscene. They chanted together and called forth Meteor.


Battle formations

Similarly, melee jobs could stand in certain battle formations to increase defence or attack

For example, one such battle formation could be: Wall where player stand in a wall and bar passage to the mages and archers.