I've painted them up as two separate units - one a horde of feral world plague zombies and the other in the colours of my cultists (the yellow-white uniform).
The gravestones are really old metal sculpts. I don't know who made them or if the company is still operating, but if anyone knows let me know because I'd like to buy some more.
These awesome minis join my ranks of 40K/sci-fi undead, as feral world and dead cultist zombies, but will also be the pawn pieces in a giant chess set I'm making (the reason I decided to put 2 miniatures on a base was to make it look more like a zombie horde on the chess board - the opposing player's pawns will just have 1 miniature on the base). I will definitely be using the Aenglish as the other pawns but not sure about the rest.
Regarding scale - they are true scale and as such are slighter that Games Workshop's more exaggerated forms, but the size comparison is similar to the Lord of the Rings miniatures (which my necromancers are converted from). I actually happen to think the scale works really well when side-by-side with my Space Marine Corpse Thralls, which seem huge, as they should. Maybe GW should scale down the Imperial troops rather than scale up the Space Marines models (just a thought).