OK, this is purely an unplanned idea that came to me while I was reading through threads over in the Fall Further subforum looking for yet more ideas for modular things to tinker with.
This covers my earlier remarks on the Luchuirp, and changing them slightly instead of potentially removing them, which as an FfH Core civ, I don't really want to do.
Golems have always been their thing, as it were, but there's also always that Dwarven overtone to them. And Dwarves are primarily Khazad.
Solution: Remove the dwarves. The majority of their units are already Golems. If the remaining non-Golem units can be replaced (or disallowed) and similarly for the buildings, I can make them a Civ in their own right.
This presents one main problem: Barnaxus. No problems there, you say? Think again.
From the Frozen module's Ice Golem pedia entry:
The Luchuirp assaulted the Illian city. Juggernauts slammed against the defenses. Towering iron golems waded through the rubble, destroying any defenders they found. The Luchuirp forces tried to stop the ritual that was taking place within the inner city, but they were too late.
When Mulcarn entered the city, entered creation, the battle stopped. A layer of ice spread from the first place his foot touched outwards through the city and across the land. The Luchuirp army was destroyed, dwarves killed, golems frozen. Even the Illian macemen were frozen in place, kept unchanged until Mulcarn needed them.
As he surveyed his new dominion he picked up one of the Luchuirp golems. He admired their fortitude. They were unaffected by the cold and their unchanging nature. All traits Mulcarn prized.
He whispered a new life into the golem, "Make me more."
"As you command" was Barnaxus's reply.
This obviously is the origin of Barnaxus' un-golem like intelligence, and the reason he can learn and think and such as a Hero. From this entry we can also discern that Barnaxus knew, or learned, how to make Golems. So, let us assume that instead of simply finding the Luchuirp, he took Mulcarn's command further than anticipated, and when the God perished, set about creating a civilization of nothing but Golems.
Without another Hero units, this means Barnaxus could function much like Basium, Hyborem, Kahd, Taranis, etc - if he's killed (destroyed) he loses his leader traits. This is however disrupted by the ability to rebuild Barnaxus, which would effectively restore them. Not sure what to do about that.
Next up, traits. Golems don't need to eat, drink, sleep, etc - so as their own civilization, they'll have the Fallow trait. Which gives us the issue of population growth. This is what I propose: The Golems can build Citizen Golems, similar to the Scions and their Awakened. These can then join the city, like Infernal Manes, allowing them to effectively build their populaton.
Organized makes theoretical sense for the Golems. They obey their orders to the letter (Unless Barny says otherwise) and they're not among the living, so have fewer concerns. They can focus on the important things, make more Golems for their tasks that are specialised for them.
This also suggests the Industrious trait, which again, makes sense. I don't want to go overboard though - making Fallow a Civ trait, and then Barny an Org/Ind leader seems to be quite sufficient.
Tile improvements. Outside of resources, farms and food-producing improvements have little, if any, use to the Golems. The only real use may be to supply the needs of the very few living people who come to their cities. They'll gain a bonus to Hammer producing improvements - Mine, Quarry, etc - that again reflects their ability to work tirelessly. This could become unbalanced, so the improvements may have to cost more for them (if that's possible, if not their units and buildings will just cost more to offset it).
Buildings. Almost all of these are now either irrelevant or unsuitable. As Golems and a Fallow civ besides, health-related buildings have no use to them. Similarly, Granaries, Salthouses and similar are also pointless. They may get a free building that replaces, but functions identically to, the Demonic Citizens of the Infernals. Golems want nothing more than to work, they cannot be unhappy or unhealthy. A bit damaged, but that's what maintenance is for. So a Golem-civ buildings would have to be completely tailored to their needs.
The Divine: As mentioned, I don't want to go overboard on traits, but Golems seem to me to be Agnostic by nature. The first Golems may have been built by dwarven hands, but this is a civilization of Golems that effectively built themselves. They know who made them and they know why they exist - to work, to serve. They have no need to follow the divine.
The Arcane: This could be taken one of two ways. On the one hand, Golems do not think as such, and one could argue that thought is vital for spellcasting - which would effectively deny them any arcane capability. However the other hand here is that Golems have a perfect (I assume) memory. Arcane Golems would be taught (or trained, or whatever) in the actions needed for each spell, allowing them to cast it perfectly every time. Or perhaps they are closer to Barnaxus and can think, in limited fashion, for themselves, allowing them to learn. In either case, this unlocks the entire arcane line for them.
With all this in mind, I think a purely Golem Civ is possible, and works lore-wise if you include that entry from the Frozen module.