Coincidentally, I was painting my Bladegheist Revenants tonight & had left the heads to paint & stick in last. The colour scheme is light on the outside of the cloaks/cowls but dark inside, and now I think it looks really cool without the heads. The darkness creates a void & looks really spooky.
No idea now if I should leave them out or go with my original plan. There's always the worry that it won't look intentional & I just forgot about them.