We commonly think of military forces as being rigidly hierarchical, and committed to following orders to a suicidal extreme for individual soldiers. But, are there examples of military forces organized in a less hierarchical and less authoritarian manner?
For example, I've heard that historically, in the U.S. military, in some cases officers were democratically elected by their men.
Put another way, is the authoritarian organization of the military actually necessary, or just a deeply ingrained tradition that could even be obsolete?