Dread Mask on the Solitaire will help you against the of the IG and <12 Ork mobs, certainly.
I think the list looks good enough, but it will be slowed, and against the firepower of the IG or mobs of orks you will be slaughtered if you don't have plenty of LOS-blocking cover. I would suggest getting a Venom to bring a 6+1 troupe (shadowseer or Solitaire) to the heart of the enemy, giving him something to worry about as your other squad (with the veil, when I think about it, so bring the Solitaire on the Venom) walks up the field with the Wraithlord as firemagnet. Good luck.