Lets say 2250 as that is the standard game in Oz.
I'd look at...
Black orc warboss with shaggas screaming sword and wyvern (other items as you see fit) for that great 1st turn Waaagh.

Also
VC tend to cluster their characters so shaggas will be going off big time. Terror causer so no psych problems.
2 mages, both level 2, 1 with 2 dispel scrolls, 1 with staff that turns 1 of his power dice into one of your dispel dice. I'd go gobbos
BSB with the dispel dice banner (put in a unit of 30 orcs)
2 giants
2 units squig hoppers
4 bolt throwers for blood knoghts, vargulfs and corpse carts
2 units 2 snotlings for redirection
2 units 25
NGs with 3 fanatics each
Whatever left over on Spider riders with musos and bows...
Start with 8 dispel dice
3 terror causers and 2 immune to psych
Good direct artillery
Good offensive capability.
Just make sure your main infantry units never see combat, they are only there as fanatic delivery and rank bonus to hide the
BSB in to generate dispel dice (I'd put this unit in a corner behind a wood)