If you look at the Vargheists carefully, I have some rackhem wulfen with resclupted shoulders to attach the wings (I'll post some closeups), and swapped out heads (obviously)
I originally had two boxes of horrors/vargheists and had a ton of leftover arms and 3 leftover torsos and a few extra wulfen to boot. So the next unit will be crypt horrors, with 1 rat ogre body (head swap), 4 wulfen (arm/hand and head swaps) and 3 actual crypt horrors
Of course Crypt Horrors also work better with a Mortis engine, and the one gw sells is just to "airy" for a ghoul army so I build one of those out of a bucket of dice, some skaven wheels and a garden of mor
Lastly I'm looking to make a ghoul king out of a rackham ork model (tbd) and a head swap.