Began a Mordor Illuvatar game. Played only 5 turns until now. Definitely, the gondorians are much stronger in defending Minas Tirith. At one moment they were walking in front of me a stack of 8 guardians, not carying of the fact that I was attacking Minas Tirith. The orcs are pretty useless against the defenders - lost 4 or 5 in an attack that only made their guardians elite and veterans. Also, the city grew at size 7. So, I am planning to pillage with the Witch-king their wheat store and stay there as much as possible. To make use of the orcs, I am planning an invasion of the southern cities of Gondor, don't really know if it is a good idea or I could make better use of them in protecting the Witch-king...For now, seems pretty challenging to take down Gondor.
On the city management side, I did my trick with selling the civilisation advance to my allies (also exchanged world maps with this ocasion). This should strengthen them and brought me some considerable money, thought not so much as when I played with Gondor (maybe the sides are not really equilibrated from this point of view?). I rushed barrows in all my southern cities, a courthouse in Minas Morgul. This way, around turn 13 I should have a nice pack of 5+ wights, maybe enough to conquer Minas Tirith? I think is worth mentioning the fact that the first time the Witch-king gained, it started a Golden Age, so my production has now a nice boost and this seems very much in accordance with the scenario too.
For research, I chose to go for the Grunds, as the one I received from start is very strong. (Did you intentionally modeled them to have attack and defense points, because the civilopedia entry says they have no such abilities?) With their movement of 2, they seem really top units.
Some things I remarqued about units, and I find a little strange, but maybe I do not have the right references to understand them:
- the orcs can not enter hils;
- the grunds have attack and defense abilities;
- I think I have seen the Witch-king produce a wraith in a previous game, though I am not very sure of this...;
For foreign relations, I contacted the Ents as soon as I could and made an alliance with them against the Elves. A couple of turns later, they attacked Lothlorien. I have seen in my previous game with the Elves that in this city is stationed Lady Galadriel with one of the rings, which gives a +100 defense points, so I thought it was imposible to take it ... well, the Ents did it, with quite a few loses, but they did it. I was really sad, because Lothlorien is my favorite spot from the all LotR world, but I suppose that, if given a choice, the tree elves would prefere ents to anybody else inhabiting it after they are gone... This kind of also secures the position of my city in the Mirkood Marshes ... but having spiders is a long term project.
The Hardawath send quite some forces against Gondor, I have seen at least 5+ units. Maybe I should do smth to strengthen them even more?
I would like to secure some elephants and maybe incense (though do not really need it) from the south, hope could use them to build some strong units. If I succed, the production of orcs will be reduced only to the cities that do not have a training hall and have a pretty strong corruption (orcs are cheap and receive an aditional hit point, so are perfect units to produce in this kind of cities), in the far north and south of Mordor.
Hopefully, I think I secured all the entries in Mordor by placing units on the spots that are passable. Maybe there is somewhere a backdoor of which I do not know, or maybe the lost wizards (should) know to create roads in the mountains? (As I understood, for now the lost wizard units do not work, so I will not worry now about this, I will leave it for the patch

.) I know that by doing this I am not really respecting the book, but my goal is to survive, right?
To sum up, it seems almost impossible to take Minas Tirith with orcs (this might account for a previous idea stated in this thread to upgrade them) but I expect that using the wraiths produced by the rushed barrows, together with the Witch-king, the army, the Grund and the Great Spider would crush the walls of Minas Tirith in the next 20 turns. If a strategy like this works, maybe there is no need to upgrade the orcs? We could consider they are good in numbers (modelled by the fact that they are cheap) and on open spaces (this could be related to the fact they do not enter hills) but not for siege. Mordor should use other units to break the defense of cities (I think grunds are exactly for this conceived, although it does mean waiting until researching them is finished).