One troll cage is all you should build, so you can being producing trolls right away. This place is much too far away from the far end of the map to be useful as a main base, and seeing as the elves never counter-attack even on the hardest difficulty, you don't have to worry about being defensive. Don't invest heavily in unit producing structures. You should build few slaughterhouses to increase your income and command point limit. When you first start the mission, you should immediately destroy the spider lair to the northwest of your base. If you picked a large swath of buffing and economic powers on the higher difficulties, save yourself some trouble and restart the campeign it's faster to repeat the first four missions and pick up a power lineup better suited to mission five then trying to work your way with bad powers for this mission. What you need are direct damage powers like the watcher and potent summons to make up for your very mediocre army. If you're like me, they're your favourite powers to boot, and you'll be in serious trouble for the duration of this mission if you've stacked up on them. Unfortunately, the force of darkness campeign power tree is filled with them. In this mission, economic and buffing powers aren't very useful. There are four classifications of powers: Direct damage, buffing, economic, and summoning. When you play the mission, your first goal is to pick your powers wisely. This makes it not only a difficult mission, but a frustrating one. The final straw is the "race" at the end of the level if you don't know about it, you'll lose the mission before your army can actually cross the map. If you didn't choose your powers well (and you'd have no way of knowing your particularly needs on this mission before-hand) you could have a very hard time. The problems continue many powers are not useful on this map orcs die in one hit from archers whether they have warchant or not, and you have no cash issues, so scavengers is not particularly useful. In other words, you have no counter to ents. The problems do not end there due to an inexplicable bug or balance decisions, ents are not weak to fire they're weak to pikes. This leaves you without many options against fully upgraded elves. All you have are orc archers, orc warriors, corsairs, mountain trolls, and drummer trolls, and five heroes that are all too weak to elf archers. You don't have access to any siege weapons, nor do you have access to attack trolls or even mumakil. You're stuck with units that are fodder, and you can't beat elves with just fodder. First and foremost, the mission does not give you access to Mordor's best units. Many players have commented that mirkwood is the most difficult mission in the game.