Why were Germanic warriors loyal to their chief?

The history of the Romans and the Germanic warriors and tribes is quite legendary, both sides had relationships with each other, incorporating alliances, treaties, and eventually war, tempestuous would be a good way to describe the Roman, Germanic relationship. The Romans viewed themselves as far superior both in culture, society and lifestyle, than the Germanic warriors. In many ways the Romans were much more barbaric, blood thirsty and megalomaniac than the Germanic tribes, even thought they