The different ethnic groups had their different system Of Govt before colonialism.British colonialism brought warrimg tribes into an entity created by the British.
Pre-colonial era,all tribes controlled their defence,economy without interference of other tribes pokenosing into their affairs.The Monarch was the head of its clans or ethnic groups.
The different ethnic groups in Nigeria could be compared to other ethnic groups in Europe

The Russians are the Yorubas,
The Italians are the Hausas,
The French are the Igbos,
Romanian Gypsy-Fulanis,
Scandinavian(Norway,Sweden,Denmark,Finland & Iceland)-Ijaw,Efik, and other riverine communities.
Make your own comparison.

Smiles

This your plug ee...he gave you expired product