I have now enjoyed a campaign as Gondor and really liked it. I have some feedback. I think, when adding 2.5 to each armor upgrade that Gondor inf/spears are actually better than Swan/Citadel when fully upgraded. Maybe the higher tier units could have an upgrade as well?
Also the cavalry is a bit unrealistic (according to me...) I know LOREWISE they should have a powerful charge, which I can live with, but they are too good in melee. In other words, they won't die. Countering them with spearmen doesn't seem to change anything. They should be good at flanking, or when armoured, able to charge right into the lines, but in my campaign I used them defensively. I could also take a full stack army with about 100 bodyguards. Visa vi, when I had inf. army I could kiss my ass goodbye when Harad had cavalery in theirs. They just can't be stopped... Not even going to talk about the black numeriarns (nazgul general).
I would like to argue further about trolls. Sure, they are hardy, but I can live with that (even though mordor has Uruk Hai when I am twenty turns from having my axemen) But it's also their way of attacking. They plow through every army, no matter how deep they are. No spearwall or phalanx can stop them, they'll just run right through my elite spear troops. Ents should be able to do that, or Elephants, but In my opinion trolls are just too small and don't have the mass for it. It looks silly. Sure, they should plow through 1,2,3,4, maybe 5 inf. but then they should get stuck. It would make it a bit more fun countering them, not having to think "oh no, trolls! Which units do I sacrifice this time?"
Also the god damn troll catapult! Has longer range than anything else both elve's and gondors couterparts. It's really annoying. I think they should have less range (Made in Mordor quality), but maybe faster reload (being strong trolls and all).