Battle for Middle Earth - Faction - Isengard

Battle for Middle Earth - Faction - Isengard
This is a hint/walkthrough post for Battle for Middle Earth. You can find an index of all our Battle for Middle Earth posts here.

Overview
Before you finish a mission/map, you should leave one enemy building standing so that you can arrange what units you want to take with you to the next mission. Unwanted Uruk-Hai units can mostly be sent to the Slaughterhouse; others can be destroyed with Ballista barrage.

In the Evil Campaign, you start with Isengard versus Rohan. Once you get Pikemen (preferably merged with Crossbowmen), you can start rushing Rohan and boxing them in early. Block their castle exits with your Pikemen-Crossbowmen and clear the rest of the map with Warg Riders. Usually, the AI will select one exit from which to send out troops (usually one of the side doors instead of opening the main gate). Once you establish which one it prefers, you can move more troops there and de-emphasize the other exits.
Two Hordes of Pikemen-Crossbowmen are typically enough to hold ground, but if you find yourself in trouble, pour on the special powers like War Chant, Eye of Sauron, and Tainted Land. The synergy with these powers can boost your troops to insane levels. Add the large squad sizes and fast crossbow fire rates and you can typically outshoot any opposition -- that is the chief advantage of Isengard. Use Tainted Land last in case the enemy uses their terrain-changing power to reverse yours -- instead, use Tainted Land to reverse their change.

When you take out a wall tower, attack the wall itself to demolish the Building Site so they can't restore the tower if they somehow find the resources to do so (the AI typically exhausts its troops in one massive rush, then keeps building squads and sending them out more or less alone as soon as it can -- but watch for behind-the-lines Elven Warrior summons).

Heroes
Saruman
If possible, use Saruman's Wizard Blast in the direction of your Uruk-Hai because you would be throwing the enemy closer to your troops. This is especially useful against Elven Warriors which you may not always be able to kill with the blast in the early game. After the blast, units usually fall (unless they are really big, like Ents) and are vulnerable to counterattack.
The Fireball is especially useful against Ents because it always sets them on fire, and Ents do eventually die in this way (but it is very slow against Treebeard).
You can use Saruman to do hit-and-run against Ents and if you are lucky you can catch two or maybe three with the same fireball, but watch out if the Ent charges Saruman and is persistent. Treebeard is particularly dangerous if he pursues Saruman as he will eventually catch up to Saruman unless he does some dodging and weaving between obstacles. Lure them between archer ranks and cut them down when this happens.
In the early game, Saruman's area effect attacks will be invaluable against stopping Rohirrim charges until your forces can be properly protected by Pikemen. In the mid-game, his Wormtongue ability can be used to distract the enemy while you advance -- very useful if the enemy is sighted by Saruman before they can attack or if they have siege engines that are suddenly vulnerable to immediate attack. Also, siege engines in close proximity of the enemy typically turn to flee, and cannot attack while they do so.

Lurtz
Lurtz is an Uruk-Hai that appears in the Peter Jackson movie version of Lord of the Rings, but not in canonical Lord of the Rings as written by J.R.R. Tolkein.
Lurtz is remarkably good against enemy archers until they get Fire Arrows as they seem to do very little damage to him unless there are a lot of archers. He is also very fragile against heroes, so you will definitely want to use his Cripple power on them and let troops take over. He will also need to run away from heroes with ranged attacks as they like to take him out.
In the mid-game to late game when your crossbowmen can quite quickly take down heroes, Lurtz's ability to passively double damage makes him a good Isengard hero choice if you don't want to micromanage your heroes.

Units
Infantry - Once in the thick of combat, or if charged by cavalry, switch to the slower-moving Block formation for a higher armor rating -- high enough for non-veteran regular-Armor units to typically survive one trample. They move quickly, and in the early game can rush enemy positions to provide cover for your archers. When you get Wargs and Pikemen, these units typically become obsolete.

Crossbowmen - These have a high fire rate combined with large squad size (10), but the shorter range means you have to respond to every archer attack personally and send them forward to counterattack. Sometimes you can use terrain to your advantage by, for example, placing them behind a ruin so that enemy archers have to circle around to shoot, thereby coming into crossbowmen range.

Pikemen - These cannot go up a Siege Ladder, and any unit merged with Pikemen also cannot go up a Siege Ladder. With pikes lowered, they have much higher resistance to being knocked down during a trample, but this protection is directional -- If trampled from the side or behind, the pikes provide no special protection or damage against cavalry.

Infantry + Crossbowman - Not recommended. Infantry move faster than Crossbowmen, so if you have them mixed and give an attack order, Infantry will generally reach first, tangling up the enemy so that your Crossbowmen can fire unhindered. This is the better scenario as all units are working. If you mix them, a Guard or Attack order will only move the unit into range for the Crossbowmen, and the Infantry in front do not necessarily mean they are subject to ranged attacks first. The infantry can move around to fight, but by then it is really too late to properly keep the enemy away from your crossbowmen. The overall unit speed is also reduced to that of the Crossbowmen.
This is, however, the only combination available to you early in the game. Unless you are prepared to scrap some units after Mission 5 when Pikemen become available, try to hold on to your Crossbowmen for later merges with Pikemen. You cannot un-merge a unit.

Infantry + Pikeman - Limited usefulness. Pikes automatically lower against cavalry and will move around the unit (this does not happen with the basic Pikeman unit, and when pikes are not lowered, the unit can be trampled as usual), but if outmaneuvered, the infantry behind the pikes can still be trampled. You lose the speed of the Infantry, which is useful in quickly engaging enemy archers, but your unit is automatically protected against cavalry -- and this is the main advantage of this Horde -- you can safely move about or attack archers and buildings without fear of being surprised by a cavalry trample.

Crossbowman + Pikeman - Highly Recommended. You are basically protecting your crossbowmen against both cavalry tramples and infantry rushes. This is the slowest of the Uruk-Hai units (slower than even Pikemen on Porcupine Formation), so retreat really isn't an option. But because cavalry tramples are so devastating, having all your units automatically protected is a huge plus. Support them with Warg Riders -- Once the enemy is engaged, rush them with Wargs to flatten them on the field.
Starting around mid-game in the Evil Campaign, you can basically dominate every map with these units relentlessly advancing on the enemy. The AI tends to start with cavalry and exhaust them in rushes against your pikemen. Thereafter, if you have veteran units, you can out-shoot the enemy and box them in at their base.

Warg Riders
Once you get Warg Riders, you can generally replace your pure-infantry squads with them as they can reach the enemy faster and can trample foot soldiers. You do need to be careful against archer towers and a base with a lot of these, but otherwise they are a solid unit.
Warg Riders cannot be sent to the Slaughterhouse to free up Command Points, but you can blow them up with Ballistae.
Be careful of pathfinding in a region with turns required. If they need to do a U-turn around an obstacle, they will sometimes not be able to find that path and instead get stuck trying to run through the impassable barrier.
Warg Riders of any veterancy are utterly useless against trolls and treants.

Berserkers
These units are strong in melee and can hit multiple targets with a single swing, but otherwise are nothing special. The follow you from mission to mission but do not have levels, cannot gain veterancy, and as they do not come in a squad, they are basically expendable. They can light the mines you can build from a level 2 Siege Workshop, but so can fire arrows from your Crossbowmen (and from a safe distance), so there is very little reason to recruit Berserkers.

Siege Engines
These do not have levels, do not follow you to the next campaign, and cannot normally be disbanded. However, the Ballista has an area effect and its bombardment affects friendly units. You can in this way destroy units that can't be sent to the Slaughterhouse and free up Command Points.

Ballista
By far, the Ballista is the best as you can generally keep them behind one rank of infantry or pikemen and still have everyone out of range of the enemy archers. One or two should be enough assuming you aren't pressed for time to breach the walls. The Ballista can shoot into the fog of war, but you first need to sight the target at some point in order to establish targeting.
The Bombard ability targets a location with area effect fire, and is in general more useful than auto-targeting when used on moving units since when given a regular attack command, it fires on the units's position when it is first targeted and the ballista starts to load. The minimum range is slightly under the length of the Ballista.
You can sort-of use Bombard to help secure a choke point: If you have multiple ballistae, stagger their fire so the location comes under near-continuous fire with only a small window in between.
After you have taken down the enemy towers and possibly their postern doors, take down two or three wall sections before moving in so that you can quickly flood the defending castle with your assault force. Don't aim for the main gate since wall sections do not rebuild. If you are not harrassed, demolish the nearest buildings behind the walls you have destroyed to give your forces more space to move.
This unit is very vulnerable to all attacks except arrows (but very vulnerable to fire arrows).
The Ballista is one of the few siege engines that can trample infantry. Since it can't outrun infantry, if you are charged, you might as well move into them to take out as many as you can before it is destroyed.

Siege Ladder
You can pre-select a unit to temporarily merge with the ladder. As soon as the ladder is placed, the unit goes up. If you win a mission before the unit has been un-merged by being deposited up a wall, you lose the unit (it does not continue to the next map, probably because ladders and other siege engines do not follow you from mission to mission).
Once placed, a ladder cannot be moved unless the wall is destroyed (e.g., with your own battering ram), in which case the ladder takes a bit of damage but comes free and can be redeployed.

Playing Isengard
For army composition during the Evil Campaign, you can get away with a 600-point (maximum) army, but it is probably more comfortable to be just a bit short so you can start building ballistae early in the mission (5 points each). If you have a maximum army, you will have to wait for some troops to die before you can build any siege engines; or, you will have to use the Balrog to smash city defenses for your army to enter. This becomes trickier against Gondor because you cannot secure a deployment zone for your army outside the walls without siege engines as their wall towers cannot be destroyed with fire arrows (unlike Rohan's wooden walls and wall constructs).

I recommend having 8-9 units of of combined Pikemen-Crossbowmen (400-450 points; split into 2 or 3 teams, depending on their veterancy level) and 8-10 units of Warg Riders for a good trample (160-200 points). Although so many Warg Riders means many will stand idle while attacking a building or small base, having so many gives you a solid trample and you are pretty much guaranteed to flatten any enemy infantry unit, buying your own units time to fire back without enemy archer counterfire. Save a few points to get a Ballista for sieges, although once you get the Summon Balrog power, you can use the Balrog to tear down a section of wall for you.

Fighting Isengard
By mid-campaign, the AI receives a lot of pikemen (sometimes veterans) to start instead of having to recruit them from scratch at a level 2 uruk pit. This means you will need to be careful about trampling in the early stages of a mission. Otherwise, use fire arrows and tramples. Wargs do not seem popular with the AI unless scripted or already provided.