Here is the definitions for the generic cultures as laid out in Central casting.
Primitive
Primitives do not read and write their own langauge and do not form significant permanent settlements. The chief industry of primitives is the procurement of food, usually by hunting(traditionally a male role) and gathering(traditionally women, children and the elderly). They do not work metal and organized farming is still rare. Political units are the family and the clan. Rulers are the most powerful hunters of the group. The elderly are revered for thier wisdom. Historical Primitives include most prehistoric peoples, many Amerindians, Artic tribes, Australian aborigines, African bushmen and pygmies. Fictional example includes J.R.R. Tolkiens Woses.
Nomads
Nomads rely heavily on livestock that can move as seasons and resources dictateand are rarely agricultural. Most Nomads are mounted or use beasts of burden to trasnport belongings. Nomads organize along family group lines, do not settle permanently, and do not develope abstract writing beyond the level of pictographs. In most Nomand tribes and clans, all adult males are warriors. The Nomads may also be skilled in other crafts or professions (rarely metal working), but skill in combat is a necessity for survival. Examples of historic Nomadic cultures include: Bedoouins, ancient Huns, Gypsies, Sioux and other plains Indians and Afghan shepherds. Fictional J.R.R. Tolkiens Easterlings.
So for Shadow World I think the Rhiani tribes fit this.
Barbarian
Barbarians are generally thought of as crude and semi-literate. In fact, they are not. Barbarian cultures are dynamic, often highly educated societies with a keen sense of propriety and law and order. In a sense, they are pre-civilized - Organized but not yet developed(or degenerated) to the point where central goverments are needed. They normally have a solid economy with defined division of labor (occupational specialization). Organized religion is often a central pillar of their society (and may dominate it). Barbarians are generally led by strong charismatic warriors, but much of the people are governed by extended family groupings such as clans. Like the Nomads, most adult males are warriors in addition to any other profession that they follow (although, like the Vikings, they may put this skill to work pillaging as opposed to warring). They may live in small cities, which are often not much more than semipermanent camps. Historical examples include feudal Europe (period of Charlemagne), Guals, Vikings, pre-19th century Iroquois and Cherokee Indian tribes. Fictional J.R.R. Rohirrim.
For Shadow World hmm How about the people of Xa-ar and some of the Emer cultures.
Civilized
Civilized cultures are most often noted for central goverments (which seem to exist solely for the purpose of colecting taxes) and large cities and stocked with the dubious benifits of civilization - Table manners, royal dynasties, wizards, professional thieves, naval warfare, civil engineering and of course, tax accountants. The hereditary warrior classes have become landed gentlefolk as knights and samurai are replaced by paid soldiery. Historical examples include: Persian and Early Roman empires, Imperial China, Selenium kingdom, dynastic Egypt, fuedal Japan, the Incan empire. Fictional example J.R.R. Tolkien's Gondoreans.
In Shadow World I think the Rhakkaan empire, Sel-Kai, and Namar-Tol, Stroane are examples.
So those are the difinitions I was going by.