I extracted the files from the addon, and the models DO work in Gmod.
I was wanting to see if anyone would re-work the models so they could use Combine Soldier animations instead of L4D2 animations. The models are rigged, but they are not hexed.
I already have a Hexer who can do this, and I will post the hexed versions as soon as I can. For now, here are the models and their files: https://www.dropbox.com/home/Helghast%20Addon
Just install these the same as a skin, they replace all the survivors.
If you do take on the task of re-working these models and hexing them yourself, just know that I won’t post the hexed versions if you make them yourselves.
I wish you luck if you do take this on, and I hope we get to finally see some Killzone NPC models!
(PS, if you do playermodels then feel free, I would only like the ones with Combine animations.