Now that's a big horde army! One thing that has to change is the combination of the Staff and Wotnotz of the Great Shaman. You can only have one arcane item, so maybe give the wotnotz to the shaman with 2 dispel scrolls and give one dispel scroll to the great shaman.
Other things to consider:
Heroes - add mad cap mushrooms to your NG big boss. Lots of fun if your fanatics hit!
Core Units - great sized units here, ideally gobbo units should be 40+ in size IMO though!
Special - If you have a few points spare, add spears to the crewmen of the chariots. S4 on a charge is more likely to wound than S3.
- Try adding a rock lobba too, not too many point's needed to include it!
That's it!
Nice list!