Hello, I'm a long time Civ player but new to Mods, and very much interested in this Middle Earth Mod, being a Tolkien nut and all. I don't know how easy/difficult it is to do this but if I might offer some suggestions as per the request. I take my sources largely from David Day's Encyclopaedia as well as the books. I've tried to provide candidates that are still around in the 3rd Age - as many of the more obvious religious candidates were largely in Beleriand, Numenor or on the Southern/Eastern coasts of Valinor which are now inaccessible. Here are some of the best candidates. I hope it helps.

City States:

Religious:

Almaren - The Isle of Almaren. In the midst of a Great lake in ME - It was the 1st dwelling of the Valar during the Age of Lamps (located south of what became Mordor) during the 2nd Age of the Sun (this is from about 10,000 years before the events of LOTR onwards). It was an idyllic place with many godly temples and dwellings. It was destroyed by Melkor though when he attacked the Valar so you mightn't want to include it - but looking at the maps for the formation of Arda it would seem the Great Lake evolved into the Inland Sea (Nurnen) that is south of Mordor and South East of Harad, bordered with Far Harad - although at the time of the WotR Sauron was using the land immediately north (Nurn) as an agricultural food basket with enslaved humans. Aragorn freed the peoples after the WotR and returned the land to the Nurn people.

Militaristic:

Druadan Forest -

Home of the Woses. Known in the time of the War of the Ring as the 'wildmen' but this is inaccurate as the name is a corruption of 'Druedain', their Elvish name. They were allies of Gondor during the WotR, King Elessar granted them autonomy over their lands after defeating Sauron.

Rhun - Land of many different groups of Easterlings.

Wainriders? Largest most troublesome group

West of Rhovanion and North East of Mordor.

Religious/Cultural:

The Laiquendi - The Nandor (Green-Elves) - 1 of the 3 Kindred of Elves that never went to the Undying Lands. 2nd only to the Ents as Protectors of the Forest.

Lindon (the land in the BLue Mountains left after the sinking of Beleriand) is their home (named for their song of lament). They are tribal and don't build cities, prefering to ambush invaders due to their promise never again to attack The Enemy after losing their King, Denethor in a battle with the Grey ELves against him. Thought they would be good candidates for a CS since they have no cities.

Woodmen - Descended from Northmen (some of which became Eotheod and eventually Rohan) Related to the Beornings their allies, also allied to the Woodland Realm, and lived in Mirkwood. Helped reclaim Mirkwood from orcs, spiders and wolves during the WotR. Were given the woods of East Lorien after the War.

PS - I'm still researching for religious CS's, but the problem is who canonical you want to keep it (timeline-wise). Many of the obvious religious choices for CS don't exist in the time of the WotR, either through destruction by Melkor or Sauron or from cataclysm as a result of the consequences of ancient wars/geographical disasters.

If timeline is less important, then there a few candidates from the 2nd Age that would fit the bill for religious CS's. Email if you need further assistance. Happy to help.

Peace!

Harad seems to be a rich vein for religion.

Bellakar (city in Harad)

Cult of Batan an-izindi (Path of RIghteousness, Path of Truth, the Enlightened Path)

Believe in equality of all peoples, Southron & Dunedain alike. Eru Worship. Valar as saint worship permitted.

Urud an-Khibil (Mecca?)- A monastery to this cult existed here. Although the Monastery was destroyed the cult remains up to the 4thAge.

Thanks for helping out. It's very easy to implement new city states and I'm happy to have some religious ones that follow cannon. For this mod, the timeline and location aren't important. However I am working on a True Start Location mod/map of Middle Earth and both timeline and location will be important since the first maps I will create will be of the third age.

Try adding Gandalf as a Civilization

@Jyackson yea that's not possible. . . he's kind of included as a city state using a different version of his name, but if i had a more accurate religious state to replace it with i will.