There probably wouldnt be too much CD terrain unless its a tower of a fortification. Hobgoblin huts or camp sounds cool though, maybe some kinda of hobgobbo look out tower. I imagine them as the outer ring of defense/alarm.
Hobgoblin shelters sound great. I’m no modeller but I shouldn’t imagine they’re too hard to create… Cardboard tube with a conical tube on top for the roof a door cut in and good bitz added eg. Shields,skulls and spears. Maybe try to make the roof or whole thing covered in animal skins or furs with stitching. Aim for a very rough orcy look.
I´m planning to make my terrain a mixture of mines, volcanoes and a dark ancient mesopotamian city, with a big zikkurat as center, probably surrounded by a couple smaller ones and densely built living quarters… think Babylon in Oliver Stones “alexander”, but twisted and black! (and smaller scale - it´s still supposed to be a smaller outpost, not a large city! )
I think that a classic steam punk look would be cool.think about the iron demon FW kit, because that could give you some idea for what buildings would look like if you can see the design in the warmachines