The translation of army lists from Warhammer to Warmaster retains only the key essence of each army. For Chaos, that’s brutal close combat strength. The Warmaster Chaos list has no missile troops, artillery, or other subtle units, just brute strength.
My army uses a Nurglesque colour scheme with green and decayed bone white as the main colours. The units are all unconverted default Warmaster models so the Nurgle link is based on colour scheme only. They could just as well just be a generic chaos force with green clothing.
Leaders: Chaos characters have high leadership and usually only a small number of brigades to command. As a result I only have one of each character option and never felt the need to get more. I am using a spare Harpy model as a Sorcerer on the rightmost base as the original Chaos Sorcerer model got lost somewhere. The Hero or General can also be fielded on a Chaos Dragon for some added fighting power.
Infantry: For some reason my two starting boxes for the Chaos army contained less Warriors and more Marauders than indicated on the cover. As a result I have six units of Marauder and only two of Chaos Warriors. I found this to be actually quite practical as the Marauder add some relatively cheap volume to the army while Chaos Warriors are rarely affordable in large numbers anyhow.
Cavalry: The strength of the Chaos army is its shock cavalry: Chaos Knights and Chariots.
Marauder Horsemen and Chaos Hounds provide cheap screening for the heavier units and especially the Hounds are a great way to add to the break point of the army.
Monstrous Creatures: The Chaos army doesn’t have big monster but Dragon Ogres can easily cover that gap. In fact, even a single Dragon Ogre is often as powerful as a larger monster in other armies. A unit of them is a powerful (and expensive) force on the battlefield. Chaos Spawns on the other hand are the one quirky unit choice in the list. I have never found a particularly good use for them but have two in the collection for completeness sake.
Flyer: Harpies are far from the best flyers in the Warmaster system but the Chaos list has no alternative when it comes to the destruction of enemy warmachines at long range. I used fewer models per base to give them room to flap their wings. As a side effect this left me with almost a second unit. One day I will find three more models to complete the missing stand.
Daemons: Chaos Daemons received their own dedicated army list shortly after I finished the Chaos army. I had a small collection of left-over Nurgle models from the old Epic Space Marine game. Though the models were designed for a 6mm scale, they are actually larger than the later dedicated Warmaster 10mm Daemon models. Since my set of units isn’t sufficient to be fielded a as a stand-alone Daemon army, I usually use them as count-as models. The two units of Plaguebearers become Chaos Warriors, the Beasts of Nurgle become Chaos Knights and the Great Unclean One Greater Daemon becomes a Hero model.