Which monsters are under/overrepresented in their threat level?

Martyrs are tougher than their threat level indicates.

Banshees will kill your entire army if you don't have some way of hitting them with enough magic damage. Even if you can inflict magic damage they can do a lot more damage than you would expect when facing one unit which is officially "Medium" difficulty, I think.

yes, the banshee 'wail'  (scream) does great damage.... and banshee is immubne to all but magic of a certain sort...

Ignys are usually very easy to kill. Even the groups of 3 don't take much to kill.

I've actually found that the skeleton groups are counted as "weak" but should be counted higher in both XP and threat rating.  The effort that it takes to take these guys out can be pretty taxing.

Air (really, any) shrills are far easier than their rating.

This is an excellent thread idea! Lot's of good info ideas can come of this.

Alas, I have nothing to add myself, but encourage others to post thoughts here.

Air shrills easy? They are a nightmare early on, you know they are easy to kill, but those static blasts or whatever it is just keep killing your units/champions

I'm quite relieved when I come across air shrills. 7/10 times my units resist. Definately my preferred shrill to fight against.....other than perhaps the water shrill.

I want your RNG, my units never resist. You playing with ironeers or something? (I play ridicilous setting on mobs, so maybe lower shrill levels help you as well?)

My current game is with Ironeers....but my favored faction tends to be Amarian.

settings are hard/hard

I find that those three demons protecting the Ascian Collar are REALLY easy to beat. Maybe the threat level is right....but this battle should be more difficult.

I actually find shrills quite dangerous. If they really get going targeting a low hit points unit they can kill something, and I hate losing units in battles. They can usually all get off at least one attack each before I can attack them. I want fairly strong units and a way to bring the fight to them quickly if I'm going to attack them.

As others have noticed it may depend on what difficulty level you're playing on. On Ridiculous I want to be pretty confident I can kill them in two or three turns, maximum, as they have quite high initiative, quite high damage, and there doesn't seem to be any cooldown period for their special attack. A spell like Titan's Breath to make them all miss a turn is very handy, as well.

The cooldown was removed as of 1.1 I believe...

I'm starting to think that there should be young dragons with the big dragons if you wait enough turns. 

Butchermen can be surprisingly tough at the start of the game. A couple of times I've been cleaning out all the weak lairs around my capital, moved onto medium lairs, until there's just been a medium butcherman lair. And I look at it and think, "how hard can it be? Low hitpoints, no armour, small unit sizes... I'll burn a bit of mana and it will be fine." And then they kill my entire army.

The problem is that if they kill one of your units they gain a unit member, which can tilt the battle quite dramatically in their favour. Bearing in mind they have high initiative and high critical chance and counterattacks, when you have weak starting units with low hitpoints and minimal armour, the chances of them killing one of your units is quite high.

I'd put Assassin Demons and maybe even Corpse Spiders in the same category. I don't think the Threat rating is too low exactly, not like Banshees, but they need to be treated with respect. Go in with a stronger army than them and it should be straightforward. Go in with an equal or weaker strength army, relying on your superior tactical abilities etc., and you can find yourself losing pretty rapidly. High initiative, counterattacks and high poison can make for a bad day at the office. High initiative, counterattacks, criticals and gaining unit members when they kill your units can bring your plans for world domination to an abrupt halt.

I did see a mod that did just that ... not with monster spawns mind you ... just with Dragons you recruit to the cause...

Just my opinion on the shrills; I have been playing on Hard/Expert and don't recall ever even having a close fight.  They only do about 2-3 damage with each shot and, for me, don't seem to focus fire often compared to ranged units in a faction's army.  Then they go down in one shot from anyone once you get to them.  And water shrills will just sit there and spam slow on units that are already slowed... 

Sure, I wouldn't take my Sov and two starting units against them on turn one and expect to come out unscathed, but they're usually listed as "Strong" groups if there are 5+ of them, and I just don't think they stack up against, say, a group of silt skaths/hergons and a troll.  Or a single Umberdroth.  But then it's obvious the game has a pretty wide view of any particular strength level, other than weak.  "Strong," especially, covers a very wide spectrum...

Side note: they're especially easy if you play a Beastlord, as a lot of the low-level beasts move incredibly fast and can close on the shrills in one turn [scratches Timber Wolf behind the ear].  Or if you've gotten wolves or archers from quests.

I definitely agree on the darklings and ophidians.  

Regarding banshees, they're hard to rate because yes they'll kill your whole army if you don't know they can't be hit with weapons the first time you face them [blush], but one Flame Dart and they're toast.

Just came across Bonesplitter. The Quest says he's 'Deadly', but when I see him roaming, he's only 'Medium'. After engaging him....he probably should be considered 'Stong'.

The typical Haunter-led armies seem to be somewhat underrated; the beasts ALL use poison, and haunters use both Mass Curse and Curse of Cyndrum.  Poison is somewhat nasty given the difficulty of increasing resistance to it -- there's Trog blood, but you probably aren't getting that in any quantity; and it's not covered by Nature's Cloak the way fire/lightning/cold are.

Haunter armies are... Well, a threat. If you haven't got good ini and good movement, the haunter himself can turn you to shreds . A good mass curse makes for really painful hits from the rest of creatures

As for shrills, I actually hate fire and air the most. Water and earth are just a matter of slowly engaging and managing your weak units (taking them away before they die, etc); but fire can hurt a lot and air is definitely awful when you still have weak units. 

I, however, don't find maul units that very hard. While it is true that their maul can get really lucky, most of the time, if you make sure you only leave one unit close to them (the one with highest dodge), you can be almost sure it is going to be barely more than one single hit, two tops. 

Dragons, however, I do not find needing smaller dragons along. But I usually have armies of glass cannons (my sov tends to be mage, for instance), and their breath can wipe out an army in no time. Hell, I've had experiences of a dragon eating up in turn 1 my defender (with the fire res. trait), leaving the normal units to "tank" Their breath is really dangerous... I end up always trying to summon something close to see if they decide to use it against THAT unit (in which case, the mass summoning of skeletons is just awesome!).

The ones I really see underated are the panthers. They are medium only technically: with their counterattacks and their initiative, you can be torn to shreds in a matter of minutes. Against them, spears are SO worth it

Agree. Good for leveling early.

Ignys are a gift. They provide a ton a xp and a high level loot for almost no challenge. You can kill them with a lv 3 hero and the starting units, bumping you up like 2-3 levels.

Darklings and Wildlings cant hurt units with shields and a single piece of leather armor.

Casting Wither on Darklings can reduce them to zero attack, at which point it becomes a walk in the park, regardless of how many units they have.

Aren't Haunter armies Deadly already? Seems about right.

There's something funny going on with those Ignys:they are fairly weak by any standard, yet their threat rating is strong and it takes many levels before you can summon them.