I've always been a big fan of Bladegheist over Grimghast- and with the point difference being so small now and the ability to get them to pile in twice and attack with the Neromancer- plus a charge that's 6 attacks a piece in a single phase!!!!
Chainrasp are a good alternative but do a very different job for me than wolves- I like the wolves movement to grab objectives early and the rasps to bog things down. So an argument for taking both.
I played a 600point game (tiny i know) last week and the dreadblade as general (Gryph feather her too) teleporting to grave-sites to bring things back and cap objectives was a complete must for me just like @Qrow suggested. And just to back up the harridans point I've been running 20 in a 2000point nighthaunt list since the start, those 3 attacks on 4's and 3's- especially with a torment nearby to re roll ones is solid!