Just want to say really cool work. I was wondering if elf or human body model might work best, but I am guessing the thinking behind that is that they are recognizably distinct from any other race even while wearing helmets.
If they are in future worked further upon, it would be cool if the heads could get scaled down a tiny bit. They should also be taller in height. Races of Faerun 3e (pg. 134) describes hobgoblins as having a general height of 6 and a half feet, which makes them slightly taller than an average human. Also, for art advice (if they ever get unique head models), in lore (again Races of Faerun 3e pg. 134) and art goblinoids generally have (not always, especially with bugbears) protruding fangs rather than prominent tusks like the orcs.
Also imo human heads 33, 34 from vanilla NWN1 were clearly made with hobgoblins in mind, could they be converted to hobs?