I don't recall off hand but how many points zombies are but he may have the bare minimum to play a 2000 point game if he goes for the full load out on them. Either way, you need a lot of core for
VC only because they are cheap and you need them to tarpit. Your core (with the exception of Ghouls) will hold a unit in place. Your more elite troops such as Ghouls, GG, Black Knights, Blood Knights, etc. will actually grind the enemy down. Ghouls shouldn't be charging the front rank, they should be hitting the flank. It will negate the enemies ranks, increase your combat res, and you'll have more attacks than the enemy due to the facing of your models. If you can get 12 attacks to the enemies 4-5 is much better than taking the brunt of the enemies attacks because you hit their front line. Models have to direct their attacks at the unit they're in base to base with (unless they're in
BTB with more than 1 unit which only happens on the corners.) The zombies will take the brunt of the enemy attacks while the ghouls will chomp away at the rest of the unit taking fewer casualties. Zombies are cheap to raise and you get more when you raise them over the other units so you don't worry about them as much.
If you had about two 50 man units of zombies you're looking at approx 350-400 points and you can force the enemy to hit them first. You just have to position your support troops so they can reach the enemy. Throw a Vargheist or the new big Ghouls in between the two units just shy of the front lines in the center and they can hit the flanks of your enemy after they receive the charge. Just have a Necro or
VC in each of the big units to boost the Zombies
LD and they will be steadfast. If you put a
VC in the unit, just make sure you challenge if you need to. The Hex Knights make an interesting unit as you can charge through their units. I don't recall if you can go through your own troops though. Either way, if you put them behind another unit so they can't get sniped by magic, they will hit like a load of bricks and you can hit more than one unit by charging through their units