Tying into the last post on the Monastery of the Sword...
A design principle for Terrae Vertebrae was that initially that the races elder to humanity had an influence on different cultural strands of nations and states in Vertebrea. Succinctly put, contact with polytheist Dwarves drew out one set of religious impulses; contact with pantheist Elves drew out quite another. This wasn't quite carried over as fully as it might be into the full thing, but the shaped stone was re-used.
So then: Dwarves are polytheist, individualistic - libertarian even. Not unwilling to cooperate with one another, but rather self-reliant and self-driven. This notion of the Dwarf is in part a reaction from what has been before.
(No Scots accents. In writing this, it did occur to me that the dwarf of cliche might be seen as a melding of unpleasant Caledonian stereotypes: Dour Calvinistic pennypinchers and/or drunken berserkers. This needn't be the only route for Dwarves. I recall one conversation about a Renaissance Italy inspired setting in which Switzerland was an inspiration: mountains, independence, banking, heavy infantry.)
Further, there's something rather grounded about this, in terms of how it fits together. If anyone can do the whole 'pulling oneself up by the bootstraps' affair, or is able to live self-sufficnetly away from civilisation, it will be the folk who endure hardship better than humans, or are better craftsmen, or can carry greater loads. Dwarf as self-made man? If you like.
Elves (same link as above) are panthiest and community focused. If everything is divine, everything deserves respect. Vegetarian aside from when a beast must be culled- they can innately sense when this is acceptable. ‘Utopian’ culture [peaceful and harmonious to inhuman or impossible levels; good-place and no-place]; innate understanding and empathy for the group. Would be confused and distressed that a human does not want to join in the games. This descends by stages into something that reaches the faintly dystopian as things get altogether Brave New World or altogether silly as things start to resemble the Flower Children of the 1960s - or an understanding thereof.
At least since Tolkien, Elves have been in touch with nature; being sensitive of the world around them and the people of it. That the keen-eyed and long-lived would become socially apt and unwilling to disrupt is not perhaps surprising - only a little less sensical than libertarian Dwarves.
Here is one set of opposing influences. Another is the Giants and the Fey.
The Fey I did not spend much time on, beyond imagining them to be out there, much of a piece with Clarke's Jonathan Strange and Mr Norrell. Whimsical, otherworldly, cruel, immensely powerful but bound by codes of manners.
The Giants are described here. Vast humanoid beings, adept in the ways of the world, intensely physical. The inspiration is more Jack the Giantkiller than Jotunheim, but the Nephilim and Tim Powers had a lot to do with it.
The Giants are of the world and things physical; the Fey are of another world and things magical: appearances, illusions. A Giant is, in stories, often easily fooled: their senses, however acute, are deceived. The Fey are repelled by the things of this world: iron, notably. Even common courtesies such as being thanked; codes of obligation and respect. Rumplestiltskin even resisted having his name known. Of course, a Giant as such is altogether too much to be put into a game - hence Half-Giants. The Fey equivalent - which I never as such concived - would likely be the Changeling.
Finally, then, the Caprine. The Faun and Satyr. What are they? What do they represent? I have thought of them as wilful (not untrue) or worldly (if not in the Giant physical-power definition of the term). Neither is untrue, but neither seem enough.
A solution: they are the 'Southern' influences of C. S. Lewis's The Pilgrim's Regress discussed and more fully defined here. Just how Southern is a matter for individual Caprines.
I never fully conceived of a Northern kindred to set against them, though less worldly Lewis creations like the Sorns did occur to me. The Pilgrim's Regress does have Northern - and deliberately non-human - Dwarves, though the term has been used already and to represent something different. But the rigid systems and rigours of Northern life do suggest a cousin of the Dwarf: the Duergar - or the Dvargir of Veins of the Earth, devoted only to Work and Blood (which is very Northern; just ask the giant Savage). Not that the Caprine-opposite would necessarily hit those extremes. Centaurs - so often portrayed in modern works as wise and stern sages - might be another alternative (perhaps they have rejected their wilder past, and thus cling to strict rules).
This is all very interesting, but what use is it?
Well, the balancing point of all this is Man; the neutral, the centre ground. If you will.
But let us imagine a setting - let us call it Ante-Eden or Proto-Vertebrae - before humanity is created and placed in Vertebrea. There is explictly a Creator, but a distant one. It may be the Eightfold God, but there is no Eightfold Faith - for reasons best known to the Creator, Aspects of the Godhead or such concerned
These six proposed races exist in a land (Giants Proper and the Fey in the background). Those races opposed to one another are in tension, possibly even conflict - with allaiances of convenience with the other four.
The six races can fit nicely mechanically into the classes of The 52 Pages. Dwarves and Elves are pre-existing, Caprines replace Gnomes, Half-Giants as Fighters, Changelings as Wizards. 'Northerners' (centaurs/sorns/duergar) are Prophets: limited in weapon selection - they are only trained or restricted by a code to one weapon - and limited, if skilful in choice of spells (unless heterodox wizards). Rogues rather slip to one side. If nothing else, this is an explanation for the different powers of Character Classes.
This would be sufficient by itself: adventures in a young land, full of energy and antediluvian beasts. A party of adventurers driven by contradictory impulses.
But then a legion of angels claim a patch of prime real estate and start laying out wonderful gardens. How will these protagonists respond to the coming race? The promised capstone of creation? Will they make common cause with a Miltonian Lucifer-analogue? Will they welcome the new inhabitant of the world? How disappointed will they be in humankind (as personified by Ask/Embla, Meschia/Meschiane, &c.)?
[To return to Lewis again, you may wish to read Perelandra.]
This is fertile ground - though it seems quite devoid of ruins and dungeons. Not to mention a theological mire. But fertile enough that I should like to put together a Changeling class for The 52 Pages, and to sketch out the Northerner or Anti-Caprine.