I think is a good list, but you may struggle a little with board control, as once the Grots will be gone you won't have anything to reasonably hold objectives. I'm putting a few ideas below:
- You should have at least one 10 man wrack unit, to properly use black cornucopias
- I would always suggest to have one skyweaver with bolas in each unit. It saves point, it can be the first to die and can be surprisingly useful against marines
- You may want to consider including Yvraine (on top of the shadowseer), as between casting on 7 and being alone, the shadowseer could be denied quite easily by many armies.
- You may want to consider a second haemonculus, to be able to send the two units of grots in different directions but still keep the +1T
- Not a fan on deathjesters, but that's very personal.