There are a number of different assumptions to unpack here. Firstly, you use the example of Ivar the Boneless, a rather famous norseman. The Norse were of course settled agricultural people. Secondly, "boneless" is a nickname. His 'proper' name was Ivarr Ragnarsson.

The use of nicknames is not limited to 'tribal' people either. Bloody Mary, Maria the mad, and countless other European monarchs had their own nicknames just as strange as Ivarr's.

We continue using nicknames with politicians and sports stars.

With regard to the Lakota and other native groups, their names for people and places are very reminiscent of groups in many other parts of the world. Names such as "Smith", "Joseph", or "Loch Ness" reflect attributes held by the subject. When we translate native words into English, we are replacing that direct link between word and subject with a number attributes we don't identify. Tȟašúŋke Witkó becomes "Crazy horse", Loch Ness becomes "Lake on the river Ness" (near Inverness or "Mouth of the Ness"), and so on. We don't notice this pattern in our native language because we're culturally desensitized to the pattern.

Colorful epithets in Ivar's time were hardly restricted to the Norse. Both East and West Francia came up with some pretty colorful ruler names in the 9th-10th centuries, from Charles the Bald to Charles the Fat to Charles the Simple to Louis the Child to Louis the Stammerer to Louis the Foreigner. The far more colorful epithets were much more an artifact of the time period than of the Norse.