I've been working with Chaos a little bit recently... In an attempt to find some sort of reliable tactic to use with them.
I then proceeded to take over the great temple using only a beastrider, a group of stickthrowers, and the huntress queen.
It's pretty simple... When you command a unit to defend itself, it will stop in its tracks and enter into "parry mode". This is basically the reverse of berserking, as the unit's effective attack rating drops to zero (they won't attack), and half of their original attack rating gets added to defense.
This means that high-attack units like the fire warriors and beastriders gain a very respectable amount of defense. And, parry mode seems to be singularly effective at deflecting attacks in general.
Furthermore, while stickthrowers may seem weak at first, they have three important statistics... First of all, their attack ratings go up very quickly when they level. Second, they've got a lot of health (for an archer). Third, they tie with dwarven axethrowers for fastest ranged attack, meaning that they can keep a barrage of sticks going. That low damage adds up after a while.
So, with his augmented defense and very high hitpoints, the beastrider can tank while the stickthrowers whittle away and stunlock the enemies and the huntress adds her own high-damage attack to the mix. Dungeons level 1-3 can be cleared with a damage report of a couple more scars on Conan's chest. I'm sure he doesn't mind.
And on easy mode, with a little finagling, I was able to have a level 1 huntress queen, a level 2 group of stickthrowers, and a level 2-3 beastrider, with enough points left over for the Amulet of Fate (an awesome artifact, and with a rather nifty +1000 experience bonus when equipped, which catapults that level 1 queen all the way up to level 5).
And although I haven't had a chance to test it yet, I think Chaos may have the single most effective method of disabling enemy mages in the game... But I'll need to check it to make sure.
Still though, Chaos is tricky... For all the awesomeness in their design, I really do think that they kinda got the short end of the stick. Their melee units die far too easily, their ranged units are ranked as some of the worst in the game (although, as shown, not quite as bad as they first seem), their summoned creatures are all melee brutes (except for the cyclops, who has an exceptionally slow ranged attack), their magic is quite powerful at higher levels, but too dangerous and unreliable at low levels to use effectively.
Their warrior champions suffer the same armor problems as the infantry, their thieves have horrible stealth (but are actually quite passable at short-ranged support combat... Which is unfortunately a rather niche use), and their mages are almost useless until they've leveled up quite a bit, which they're not good at (you basically just have to tack them on to another experience-hunting group and hope they catch something that isn't an arrow).
I also found out that properly equipped fire warlords are even more stupidly overpowered than dwarven warlords... The only thing that's really stopped his solo rampage so far was this one necromancer who kept casting Lost Soul. Friggin' cheap bastard...
EDIT: Storm warrior + Storm sorcerer lord with lightning charge = dead enemies and safe mage.
Unfortunately, lightning charge seems to negatively affect parry chances (possibly due to the fact that the Storm warrior felt the need to make big wavy hands whenever someone hit him... Bloomin' idiot), as there was still a noticeable health drop in dungeons higher than level 3.
Either that, or Storm warriors really are that bad... I'd started out with a Will O' the Wisp, but this had a slight problem... Apparently, the lightning charge doesn't go off when an attack is negated by the Will O' Wisp's 80% physical immunity. Those first few fights took a looooooong time...
Also, I apparently ran into a bug during character creation, so the Storm lord is wearing a Ring of the Four Winds which seems to have been applied four times. He now has 26 mana (at level 3), and 100% immunity to all magic (except for air, which gets 125%).