My Notes from Mod Page moved here to declutter your front page lol:
TL;DR Your telling those gor heads without DEF prefix to load body textures, not the heads.

And I don't fully understand it, but in my tests think alpha needs to be on for the dark elf slave master legs at least, while testing this I noted one set will do same Houdini trick as the two gor heads with LOD.

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So I can confirm it is the "gor_heads" 1+2 without the "def" prefix. Here's what is going on/how I fixed it:
Noticed in the LOD settings for the actual variant mesh(not the definitions) in the RFPM for like LOD Detail 2 and so on you have "bst_gor_body_01" changing that to this: "variantmeshes/wh_variantmodels/hu6/bst/bst_gor/head/tex/bst_gor_head_01_[diffuse, normal, etc]" for both 1+2 has fixed the problem.

As well I noticed the dark elf masters had disappearing legs, no errors in their file paths for textures but I think turning the alpha off caused this, tested and confirmed now this was the case, at least with 19 units of beastmen none of the dark elf masters have the issue anymore, so assuming has to of loaded all possible variants for unit right.

Should say I did this for both gor_head 1 and 2, and all four levels of LOD, and all five path files in each.

For dark elf master was just one set of legs for each of their body variantmeshes/texture files(I honestly don't know what they all are, just know what they do from trial and error xD) "def_thrall_master_body_[01/02].rigid_model_v2"

Oh last note for you, I have no clue how to change the actual names of the LOD levels(like where it still says body_01, instead of head_01), I didnt bother, fixing the file paths was all that was needed. Oh and let me know rather I just ship you the pack file I'm working on with the changes, can upload to google docs if having trouble following my ranting here lol