Again and again I've read in history books that the ancient Germans had no clear hierarchy as known from the medieval age, but very often rather informal warbands.
The story goes usually like this; a famed warrior gains followers and they march to raid something.
There's usually if not always the assertion that it was the leader's skill as an individual warrior (perhaps aided by superior equipment) that destined him to become a leader. Well, that or simply inherited reputation.
My observation of modern-time self organization raised some doubt about this.
The closest equivalent to ancient warbands are today gangs and gamer clans. The latter - online multiplayer gaming clans - are more easily accessible for observation. There are likely ten thousands of multiplayer gaming clans in the world, I've probably seen hundreds of them (at least superficially).
Not one of them was built on a "a great individual player becomes warband leader because of his greatness" model.
Instead, the typical creation of such a clan looks like this:
One to four guys decide they want to found a clan instead of being in another one. They provide essential services such as voice communication server (such as Teamspeak or Ventrilo), a forum (for communication and creating cohesion), a website (mostly for representation and recruiting), they decide on a clan name and clan tag, probably invent some clan rules and a clan motto and finally they launch the recruiting. The decisive characteristic in this first phase was to be ready to organize a clan out of thin air, not individual skill or success in the game itself.
Players join and the second phase begins; now it's sometimes necessary to improve on the services in order to keep members satisfied, but most importantly the founder team has now to prove leadership and management capabilities. Founders are almost never removed from leadership positions against their will. We live in democratic societies, but this doesn't seem to affect clan management much. Instead, members vote with their feet. They simply leave the clan and join another one if they're not satisfied. The voting is on clans (warbands), not on the leader(s).
The decisive characteristic in this second phase was to be able and willing (time!!!) to lead satisfactorily.
First logistics, then leadership. These two factors are typically (actually without an exception to my knowledge) decisive for (amateur) gamer clans - not the leader's skill as an individual gamer.
There are very few clans for ~top5% players only which have top players as leaders, but they work along the same lines as far as I know.
These leadership dynamics are today so dominant over possible alternatives (100% dominance afaik) that they appear to be strongly rooted in human (young male human?) psychology.
The model with the best individual warrior being the leader is furthermore inherently inferior to a model which requires the leader to be a good leader. It's reasonable to assume that some evolutionary selection mechanism is at work in the realm of raiding warbands. This raises additional doubts about the standard description of ancient Germanic warbands.
Maybe the thing about Germanic warbands should be re-thought.
Modern-time warbands don't seem to be built by the best marksmen or fittest warriors either. Instead, they seem to be generated by those with experiences, radios, the ability to sustain the warband and probably some charisma.
Disclosure: I do almost never play shooter games and didn't spend a significant amount of time in MMORPGs for years. My experiences are thus mostly a bit dated.