Sorceror-Prophet Nalgrund:
-Zharr-A-Tustra, prophet of Hashut level 4 on baal taurus with charmed shield and talisman of preservation, lore of fire.
Drop the Bale Taurus, it's just a way to get sniped
Lore of Fire is terrible on a Level 4, and he is your only way to get Lore of Hashut, so take that instead
Charmed Shield is good, but given he has a huge magic item budget, I'd stick the Furnace Mask on him for magic armour. It gives you an armour boost, a strong ward save and fear for a very reasonable price. Charmed Shield you can farm out to a Hero or your second Sorceror (btw where is he?)
I don't know why you're not fielding a second Sorceror, you have the Lords allowance to burn. A backup Level 4 Death Prophet is a fantastic choice, as he complements the anti-infantry magic of Hashut with sniper spells and the deathstar/monster slaying nuke of 'Sun'. 'Soulblight' is also pretty cool if you roll that, makes IG much more effective.
Dark castellan, BSB, mask of the furnace, heavy weapon.
Obviously drop the Furnace Mask
Great weapon is eh, you have decent Initiative, and with the addition of Potion of Speed, you can actually do pretty well in a challenge.
I'd recommend a Sword of Might, it's pretty cheap and striking at Initiative with S5 is pretty awesome.
Enchanted Shield and Talisman of Preservation are a good combo on him, and that fits in his magic budget with the other items I suggested. With that loadout, you get a very tough BSB who is also pretty fearsome in combat.
-Deamonsmith with chalice of blood and darkness, lore of metal.
I think it's functionally worse than just a cheaper dispel scroll TBH.
Lore of Metal isn't that great on a Level 1, I'd actually take Lore of Fire. Fireball is a great scalable dakka spell, and if you roll Flame Cloak or Burning Blades, you can make your attached IG unit pretty fearsome. Not to mention it generates a lot of hits and can deny Regen.
-Hobgoblin Khan on wolf and dracocide gemm.
-Hobgoblin Khan on wolf with spear and shield.
Dragonbane Gem is completely pointless, no one will be firing Flaming attacks at him
Otherwise, pretty cool, as they are dirt-cheap interdiction and warmachine interception units.
-Deathshrieker rocket launcher.
-Magma cannon.
-Iron demon hellbound.
-Magma cannon.
-Deathshrieker rocket launcher.
Not a fan of Deathshriekers, I'd personally take as many magma cannons as possible to burn down enemy numerical superiority.
Iron Daemon is fun, I prefer the K'Daai Destroyer for a big mean monster choice. You can take two at this point level (even with a Hell Cannon). Two Destroyers is pretty intimidating to most opponents.
-30 Infernal guards with heavy weapon, banner, musician, standard.
-29 Infernal guards with hand weapons, shields, banner, musician, standard.
-30 Infernal guards with blunderbuss, standard and musician.
-40 Hobgoblins archers with shields, standard and musician.
Not bad. I like fireglaives more, because you hit at Initiative and you get a good shooting attack as well.
I'd split up the Hobgoblin horde into two 20-strong blocks, they won't win combat against anything and being able to split arrow fire is handy at times.
Blunderbuss...eh, S3 is sorta meh, but I guess whilst you're at 30-man, the re-rolls will help.
-Hell cannon.
-K'daai destroyer.
Not bad. Not a fan of the Hellcannon, but it's still a good choice.