Angmar is a force that thrives on synergy. Few of the units in the army are strong enough on an individual basis to effectively fight against their enemies, and even fewer would be considered powerful choices within the context of any list. They are, in some ways, the exact opposite of an army like the Fallen Realms, where many of the units (Easterling footmen and pikes, for example) are relatively strong without any external support.
To win with an Angmar army, you need to understand that you are building an army of interlocking parts. They are, in essence, forced to take an army that is going to enhance each of the parts that you already have. For me, I evaluate every unit that I would add to my Angmar army with my eye on several criteria:
- How will this unit impact the overall maneuverability of my army, which is one of Angmar's main advantages?
- Are there any abilities this unit has that will increase the value of units I already am fielding, or will this unit be enhanced by them in any way?
- Are there any ways in which this unit will deny my opponent the ability to counter my most important strengths?
With these things in mind, you should be able to create a checklist for each unit that you could add to your army. Thus, when you play, you can develop a process where, after each game, you evaluate what your army did well and what your army did poorly (which is independent from what you did well and you did poorly, as sometimes you can have a perfectly viable force and play it poorly, thus losing, or play a very flawed force well and win). When you find areas where you are consistently lacking, you know what to add, and when you find areas where you are overweight, you know what units might be able to be trimmed out.
Now, to more practical concerns, here are some of the larger synergy issues in play for the force:
- The spirit formations, with high movement (8 or 12) and spirit walk, are already very fast on their own. Taking heroes to lead them will enhance this, however you are limited to captains due to the We Stand Alone rule for both the Ghostly Legion and the Ghostly Riders. Given that captains are extremely fragile in the face of an ES Duel, you have to decide if you want a lightning fast unit that has a major achilles heel, or if you want to take Shades, which will slow them down but ameliorate their biggest flaw while still allowing you to exploit their speed if they are not being threatened with ES.
- Spirit formations also have spirit grasp and terror, meaning they stress the courage of enemy formations. Thus, anything that is going to either increase their own hitting power or decrease the courage of the foe will have a major impact on the fight, as courage values are typically much lower than defense (minus the elves and, ironically, Angmar). Major synergy can be found with the Tainted as a result - denying the ability to use a hero's courage delivers the double whammy of more failed terror checks and better odds when fighting; similarly, ringwraiths in general tend to have several spells that are very useful here. Whenever moving courage a single point will change a die roll in combat (say courage 4 going to courage 3 so I will hit on 4's instead of 5's), I will often lead with Sunder Spirit to ensure I get it off, as few things are more useful than boosting the lethality of your formations. Visions of Woe, Transfix, and Terrifying Aura can all be useful follow up spells here, lending more strength to the Dismay tree in conjunction with Angmar's natural abilities than it would have in a typical Mordor list. Obviously, the Darkness spells are often solid on their own, but of particular interest here is Black Dart, as it will drain might from heroes that sorely need it to modify key rolls and duel against Angmar, so that is often an excellent follow up spell as well (especially if you can take an ES character from 2 might to 1, as then dueling a ringwraith becomes a suicidal maneuver if the wraith still has 1 point of might to call ES if it is attacked).
- Gulavhar also has quite a bit of synergy with the spirits from the maneuverability perspective, as well as the ability to call heroic fights for free. He is fast enough to keep up with them, can use them to screen his own advance, can smite characters that would otherwise try to attack your captains, and will allow you to pile on with the spirits (who are relatively good at winning fights if you are using the magic above in conjunction with the Tainted to really lay the lumber on people with spirit grasp).
- Conversely, including slower elements will increase the value of Shades, the Court of Fallen Kings, and the Werewolf Pack, as they will more easily keep pace with your army.
- Buhrdur's ambushing ability and ability to at the double means he can often arrive just as the spirits are delivering a crippling blow to the foe, and can usually keep up once he shows up on the board (though watch out for terrain, as he's not a master pathfinder).
- Conversely, taking the barbarians will often slow your force down, but provide you with a much more solid middle. Here, a ringwraith is hugely beneficial, as the barbarians pack far more of a punch if you deliver them with a charge, rather than get charged. Wings of Terror (to ensure they get charges off), Strength From Corruption (to boost their strength to a ridiculous 7 or 9 on the charge), and the fact that the wraith will cause terror are all going to enhance these guys dramatically. I prefer the Dwimmerlaik with them, as he saps the might of foes that would otherwise be acting to counter them and makes dueling him significantly more difficult. The Tainted loses some of the synergy here, as his courage reducing ability is simply not as good.
- Ghostly Riders have major value alongside the barbarians, much more so than the Ghostly Legion. The Angmar army fielding the barbarians will be engaging in a more typical battle line on a regular basis, and the Ghostly Riders are fast enough to start 6" behind the line and then move completely through an enemy formation that has maximized into a straight line to attack your own formations. Rear charges are entirely possible in this context, but likewise, you can hold the riders back and sweep around either side to deliver crippling punishment on the flank while the barbarians punch people directly in the face. Here, given that your main element is slower, the extreme speed of the Ghostly Riders allows you to hold them back as a reserve element and deploy them to where you need the punch, giving them a significant synergy advantage over the Ghostly Legion in this situation (they are not quite fast enough to leap over a battle line, nor cover flank to flank at times).
- The orcs also have more value in a straight line list, as they can serve all of the same roles that they would serve in a typical Mordor army: screening vulnerable troops, providing cheap shooting elements, and delivering 2h weapons either on the flank or to the face of the foe. Once more, a wraith with SfC and WoT makes the 2h weapon orcs vastly more dangerous, as they can reliably charge and will do huge amounts of damage when they arrive.
So my point is ultimately that the value of certain units in the Angmar army, more than most armies, depends on what you already have in your force. A single unit of barbarians in an otherwise fast spirit host will be left behind and isolated, reducing their value. A single unit of Ghostly Legion in a barbarian heavy horde, on the other hand, will likely not have enough support to be worth their points. Thus, army construction should keep in mind which units genuinely enhance what others bring to the table (and create problems for your opponent that are not easily solved), and by maximizing this, you should have an Angmar army that is at least playable, as some of the weaker choices grow much stronger with appropriate support.