As you may know a dear friend of mine, DrHouse is working in an awesome map, Minas Ithil:
http://en.modding-union.com/index.php/topic,30751.0.htmlWhy i started with the former info, because he once proposed something very interesting: why not create an ancient Gondor in the maps of the south (as Arnor in the north)?
Why? Because it will be in the same time-line of his brother Arnor! Eanur arrived with his armies, late but he arrived.
This ancient Gondor will feature the same buildings, save a new one called Library, where Gondorian favorite white wizard of that time will unlock some fortress-army-etc upgrades.
The tech tree will be almost the same as Arnor save the Palantir will must be renamed.
The outpost of course will have the fortress of Dol Amroth.
The Library could have these researches:
-Line of Númenor: Makes every heroe 50% resistant to magic
-Abandoned fortresses: Every outpost & castle becomes cheaper by 25%
-The scrolls of isildur: The ring heroes gain -25% of time recharging
Ring heroes:
-Eanur
-The white wizard
Hope you can improve it with your awesome ideas!