We should stick with those involved in the conflicts at Minas Tirith and Helm's Deep. The Rhun weren't there, only Rohan, Gondor, Hobbits, Elves, Dwarves and one Ranger on the side of the Free, so only Eriador, Gondor, and Rohan. And technically the Corsairs never made it there, but they would have been if not for Aragorn's journey down the Path of the Dead. The enemy should be Mordor, Harad, Corsairs (consider them seperate as they were see going pirates, not oliphant riding "savages"), and Orthanc.