As with Chaos Daemons I took the liberty of constructing a comprehensive list of what units should be in TWW3, this time for Chaos Dwarfs. I also took the time to see if a Hobgoblin army was possible and after some researching I could see it being possible. Lets start off with Chaos Dwarfs.
-CD Warrior (Hammer)
-CD Warrior (Ax)
-Infernal Guard (Ax)
-Infernal Guard (Blunderbuss)
-Chaos Siege Giant
-Deathshrieker Rocket Launcher
-Iron Daemon (Steam Cannonade)
-Iron Daemon (Skullcracker)
-Bull Centaur Taur'ruk
-Bull Centaur Lord
Most of this is a straight forward copypaste of the regular army, but with notable differences. Primarily, I did deduct all the greenskins, mainly because it would clutter things that exclusively belonged to the Chaos Dwarfs, all their beasts and infantry are distinctly from them. That said CA could still use them as slaves to man their artillery (minus Dreadquakes which need a chaos ogre) like how regular dwarf engineers do now, it's both lore faithful yet it doesn't get in the way of other units being in. This way Siege Giants would feel like the only unit directly copypasted from a previous game similar to how Harpies for the Beastmen are also used for the Dark Elves. For Legendary Lords Astragoth was pretty obvious, but I was split between Ghorth and Zhatan since once is an actual leader but the other one actually has a model kit; CA could make Zhatan a unique hero similar to Krell or Red Duke where only Ghorth can summon him. Drazhoath and Rykarth have enough information on them to make in as DLC. As for what units could be future DLC maybe have Daemonsmiths and Sorceror-Prophets have Earth lore, perhaps feral versions of Great Tauruses and Lammasu that aren't mounts; if there's enough demand DLC would be the place for Hobgoblin units if demand is high enough. As a crazy idea CA could also include enslaved Fire Dragons since there is very little lore on them, they live underground around the World's Edge Mountains, and it still maintains their fire motif.
Speaking of Hobgoblins I was able to make up a small army.
-HG Warrior (standard ax users, maybe divide those with and without shields)
-HG Archer (maybe have a variant that use poison arrows to reflect treacherous nature)
-HG Wolf Raider (Sword)
-HG Wolf Raider (Ax)
-HG Wolf Raider (Archer) (poison arrow variant possible here)
-HG Bolt Thrower
-Gorduz Backstabber (LL)
-Oglah Khan (LL)
-Ghazak Khan (LL)
We got two units for melee infantry (four if you count slaves who could be used similar to Skaven Slaverats), one for missile infantry, two for melee cavalry, one for missile cavalry, one for artillery, one standard lord, and four potential LLs. Hobgobla-Khan doesn't have a picture to the best of my knowledge, but it's very possible CA could create a design for him. Not counting the LLs that would leave ten as-is, thirteen if you include possible variations. That does leave a lot of room for what could get in and it is possible to use units that are currently not in the Greenskin roster:
-Snotling (extra melee infantry)
-Orc Bully (older orks with whips, could be used as heroes that maintain public order)
-Spear Chukka (basically a bolt thrower, could be used as cheaper but less armored and ranged versions of the regular one)
-Pump Wagon (used by snotlings as a chariot)
-Colossal Squig (gives a war beast and normal sized squigs are already in, who is to say Hobgoblins can't train them?)
-Wolf Chariot (it fits with the wolf cavalry motif and if normal Goblins Norsca could use a variation I don't see what would be stopping these guys)
-HG Spearmen (used to defend their bolt throwers, could be expanded to anti-large infantry)
That bumps the potential unit roster from thirteen to twenty. There wouldn't be a lot stopping CA from adding a handful of more units like regular versions of trolls, giants, squigs, etc. Given their geography they could even "borrow" some war beast units from the Ogre Kingdoms (through raiding, of course). It's crazy, but not impossible if Norsca and Vampire Coast are anything to go by.