Idk if he means for one battle he needs help, just general strategies

I'm just talking general strategies here.  I usually play evil too, and am quite familiar with the legions of Mordor, however I decided to do good for a change.

Yeah, poisonned arrows do work nicely.  I'll have to grab a spider or scorpion for that poison.

The Umbar fort is besides a lake, in a fairly flat area.  I don't know if there's any way to take advantage of that.  ArcenGamer, I can't do all of that, and I don't know how many units, but a good bet is that they have slightly less money than me.  My guess is that their only defences are shooting down from the wall.  They have battlements.  I don't know what kind of units they have, but likely Umbar and Mordor units.  I have heard he has half-trolls however.  The Mordor fort is a good deal smaller, but I have never been inside, so I can't say much about it.  It's in Gorgoroth.  They have a good deal less money, and in previous battles with other players I have seen them use plenty of Ologs.

Thanks for the tips about the Cavalry!

Rangers can annihilate almost any unit, and dwarven axe throwers are good too.

I can give you some advice for general strategies: study Belisarius, Khosrau Anushirawan, Suleiman the Magnificent, and Agrippa. A couple of specific battles to look at are the Siege of Nicaea in 1097 AD and the Siege of Naples in 536 AD. 

The kid just wants some advice, not a history lesson XD

I do love history, but I don't have time, sorry.

Alright I'll break it down. Scout, scout, scout, and then scout some more. Not just before the battle, but constantly. At any point where the fighting ceases or slows down, look around for weak points to exploit. Found a hidden tunnel that the enemy didn't bother to guard? Excellent. Create a large distraction while you sneak through with a larger force and encircle them. Is there a section of the walls that are less protected than the rest? Concentrate most of your force there. 

Bring a lot of troops, who are strong, and make sure they are ranged troops because orc bombadiers are army killers, if you have any Huorn leaf it's a great way to reinforce on the move, Huorns are weaker then they look because they lack armor but they can still serve as tanks, that's pretty much it, this is Minecraft sadly, that's as far as strategy goes.

I think this is pertinent. https://www.shamusyoung.com/twentysidedtale/?p=1235

If the only limit is money, get a bunch of dwarven warriors and then as many huorns as you have time to make before the 15 minutes starts.

The only thing that really matters is engaging as much of your force as possible - if you significanly outnumber your opponent, use summon horns in the middle of his army, then hide while your units do work.