Since I did a lot of research on Neolithic cultures when Humankind first announced their 'Neolithic Start', got some input here.
First, Neolithic generally refers to the period 12,000 - 4500 BCE and is considered to have started when the first faint traces of farming and animal domestication appear and ends with the development of the first metallurgy - cold-worked or smelted copper, lead, gold, silver, tin.
It is also characterized by "the first Human fixed settlements" - but NOT cities. The earliest concentrations we can stretch to call "urban" aren't until 9000 - 8000 BCE: Jericho with stone walls and a population of 2500 - 3000 by 8300 BCE, Motza (modern name) near modern Jerusalem with 3000 people by 7000 BCE, Catal Huyok with 5 - 7000 people between 7500 - 6500 BCE - which was then abandoned for several centuries: the early 'cities' were pretty fragile and subject to collapse if things went wrong, like prolonged drought.
Second, really 'nomadic' cultures are later than the first permanent settlements: without draft animals, it is a real chore to move people, children, household goods and items no matter how primitive: until draft oxen (8500 BCE) and horses (4200 - 4500 BCE) were domesticated, no large groups were going to move anywhere unless forced. The earliest truly pastoral cultures: Afanasievo (3700 BCE), Botai (3700 BCE), Yamnaya (3400 BCE), Sintashta (2100 BCE) are all AFTER the first cities in Mesopotamia, China and the Indus Valley area (5000 - 4100 BCE).
That means the first 'pastoral' cultures were people who were in permanent settlements who discovered that they could live better by following herds in wheeled vehicles and on horseback herding their domestic animals - the same choice made by the Native Americans who moved onto the prairies in the late 18th century, in some cases after being settled farmers for some time (Comanche, Kiowa).
So, a Nomadic (pastoral) Civ would be one that makes a specific choice to be one. In every case, what led people to make that choice was their surroundings: being pastoral and able to move your 'base' meant yo could exploit wide areas, and if you lived in a place of wide areas (the Eurasian Steppe, the North American Prairie) you could exploit that environment and nobody who did not adopt your lifestyle could bother you - until centuries later when a whole suite of 'civilized' technologies allowed them to venture onto the wide Spaces and survive there.
Humankind got Neolithic right in that at 12 - 15,000 BCE everybody is in small groups hunting and gathering across the landscape, and no population concentration was possible without some special environmental niches: marshes teeming with fish and waterfowl or concentrations of wild plants and animals to exploit along lush riverine stretches. Once the small groups develop a way of sustaining the food sources with animal domestication or agriculture, they can become Big Groups and settle in one place. And Agriculture may or may not be absolutely necessary: the earliest indication of domestic cattle (at Mehrgahr in modern Pakistan) is postholes for corrals to keep the cattle close at hand as a food source, and the evidence is contemporary with the earliest indications of domesticated gains. Most early 'farming' settlements/cities also fished and hunted as well - DNA can differentiate now between wild and domestic animals, and the wild hunted types co-existed with domestic animals and agriculture as food sources for centuries.
Bottom Line: Everybody before about 8 - 9000 BCE would stat as a small mobile group (on foot). Where there is lots of food of any kind: animal, vegetable, fish and/or fowl, they can form small settlements ( 150 people and up, several times the size of the average hunter-gatherer groups that have been observed in the last couple of centuries). Whether the step up is to Cities (1000 + people) or to Pastoral depends on the Environment: horses or oxen to domesticate for mobility and wide plains to exploit for pasture, or Food Plants and fertile river bottoms that make it worth staying put and grubbing in the dirt for food.
Going back to the original subject, the Ottoman Turks, they migrated out of Central Asia around 1000 CE, but really aren't differentiated from any other bunch of pastoral refugees until the 13th century, when they settle down near the Sea of Marmara and try adapting a Turkic tribal organization and customs into a settled State whose original exceptional quality was that it accepted a wide variety of groups into their little kingdom: Islamic, Christian, pagan, and virtually all non-Turkic nationalities in the area.
