Typhus will be pleased! While these are not going to be plague zombies, they are counts as guardsman in my larger blob squads. They are mantic games ghouls (as opposed to their version of the zombie) models, and I really think that while they have limited models, posing them uniquely gives them a uniform horde look. I painted them using the same technique for the green as I did on my guardsman, however the flesh was a different combination. To achieve what I think looks like a good undead flesh skintone, do the following:
Base with Karak Stone (old Dheneb stone), applying two coats onto the black primed base. Follow up with a nice wash of agrax brown wash, to which then you paint the raised areas (muscles, erc) again with Karak. Finally, on the most raised areas do a 50:50 blend of Karak and Bleached Bone to top it off!