The issue with publically distributing content from another game has nothing to do with the EULA. It's simple cut-and-dry copyright law and there's no vague interpretation or technicalities involved.
No, I am sorry, but it's not "cut and dry." Aside from the primary purpose of establishing liability limitations, EULA is also used to assert control of content by copyright owners beyond the scope of copyright laws. We've witnessed this in the numerous locked threads about a certain utility that I will not name, which is intended to facilitate the conversion of Morrowind assets for use in Oblivion (not the public distribution of these assets). This utility is outlawed by Bethesda, according to Bethesda lawyers, not because it is in violation of copyright laws, but because it is in violation of the EULA.
This is from the Bethesda blog:
Can I import a model (or texture or song, etc.) from another game into my Morrowind Mod?
No. The position on these sorts of things is very clear. You can't take assets from any other game, including ours, and put it into Morrowind.
Pointing a mod at the resources you or your user has legally acquired copies of is unquestionably legal as far as copyright is concerned, but may be against the EULA.
Now that sounds exactly like the Bethesda lawyers....
Alas, I don't think there is any point in continuing this conversation, since the vast majority of such discussions in the past have concluded in locked threads on this forum. I don't think anyone will disagree that the OP's question has been answered?
what if you created your own textures? Would it then be legal to use the already existing assets with your textures to bring supermutants into the game?
Unquestioningly acceptable--recall how many FO3 mods were re-textures of creatures and guns.