Well I can tell you know, Dark Elves love their repeater crossbows and poisons. I dont know how your friend is going to be playing them, but look out for those crossbowmen and fellblades.
Undead; Watch out for the Vampire he is power house of the warband. I usually try to avoid him as much as I possibly can. I also try to single out his Necromancer and take him out ASAP. Also, I suggest to not bother with Zombies and try to kill off any Dire Wolves.
Witch Hunters; They are pretty scary in Melee but are a little lacking in range weapons (they still have Crossbows and Pistols). I try avoid flagellants as much as possible, or take them out with ranged weapons.
Thats pretty much the best advice I can give you when it comes to facing those warbands. I do suggest getting Hammers of Sigmar for your heroes and I will tell you know, if your Augur lives and gets a good handful of experience it becomes an awesome character