It's a matter of much debate, and historians views have varied greatly over the years. Once, pretty much all historians thought that the migrations in fifth-century Europe were all great movements of people. Now, however, many believe that many of the barbarian groups were primarily military forces. Overall, it varied massively. For instance, the Belgic settlement in late Iron Age southern Britain seems to have only been the movement of the political and cultural elite, but the early migrations of Goths into the Roman Empire definitely included a high proportion of non-combatants (this is attested by written sources and art). Moreover, there also would have been migrations such as the Anglo-Saxon ones, that included a lot of non-combatants even though if was not a case of entire populations on the move. Quite simply, it varied a great deal and there was something of a spectrum; it wasn't just a case of army or nation, sometimes it was a bit of both. The Norman conquest of England might seem like a classic example of just the elite and army migrating, but it led to a lot of traders, craftsmen and even some peasants moving from the continent to Britain.

It often varies from nation to nation, ill try to break some of them down for you.

1. Anglo Saxons: The early germanic populations of England were consisting of manily two tribes but also two smaller tribes. The larger ones were the Angles, who came from the southern part of Denmark, and Saxons from Northern Germany. The smaller ones were the Jutes from Central and Northern Denmark, and the Frisians from the Netherlands. In the cases of these population, it was collection of people who went, the entire population did not migrate, likely not even close. The angles generally mixed into the mainland germanic peoples, as did the Jutes. As for the Saxons, they were still a big force in Germany, and were until well into the era of the Holy Roman Empire. The Frisians migrated the least to england, and remained a prominant force. They ended up remaining Pagans much longer than their neighbors such as the franks, who had converted in the late 5th century, and the English, who converted in the late sixth century. The frisians largely remained pagans until the 8th century, with the Last pagan king of Frisia dying in 719 AD. After that they were absorbed into Frankish and German populations and would not see anything close to a state until the Netherlands was established centuries later. The frisian langunage is actually still spoke today in parts of the netherlands and germany.
2. The Hungarians (Magyars): Little is known about the Magyars before they are recorded during their raids into Europe, but they leave some of a trace. Although they seem to be a Uralic people of the Finno Ugric branch, the early Magyars seem to have had more in common with Turkic cultures. Their native religion was a form of Tengriism, and they were horseback steppe warriors, while their Ugric counterparts, the Khanty and the Mansi, were arcric reindeer herders. There is no trace today of a Finno Ugric people that present as Turkic, likely meaning the vast majority of the Magyars migrated into Carpathia with their chieftains led by Arpad. Their have been attempts to liken them to turkic tribes like the Huns or Khazars or Kipchaks, but their langauge does seem to be Ugric in nature, being similar to the Khanty and Mansi Languages. There is also a turkic tribe in Kazakhstan calleds the Madjars, which many, especially Hungarian Turanists (THose who attest to Turkic origins), believe to the "Magyars that never left", but no known connection has been proven.

Bro It depends on the geographical structure and environment of the place they want to take control.

The Turks who conquered Anatolia were populations and leaders

While the ones who conquered Egypt were just leaders and military generals

Because Anatolia is a cold region and it's fine with the Turks unlike Egypt which is very hot

The same case with the Arabs when they conquered spain the bring their families and tribes with them because Spain is a warm country on the other hand when they invade france the bring just generals and armies because france is cold country

Another example are the British the conquered large parts of the world yet they settled in large numbers only in places which share a similar climate with their own homeland like Canada , the United States and Australia.

The ordinary people always preferre to settle in a place which reminds them of their motherland

While the soldiers ,generals and governors don't have any problem with settling in any region