But the key difference is that the authority granted to these leaders is conditional and temporary. If the group loses their faith in the leader or the leader is no longer absolutely necessary, they can fall back to the democratic process again.
Likewise in federal communal structures an individual commune or neighborhood can always object and, if its members don't feel adequately represented, secede without threats of violence.
We recognise this level of autonomy in super-national structures like the European Union (hence the discussions around "Brexit" and such), yet we seem to treat them as unthinkable within a nation and any mention of autonomy at the communal level is easily seen as absurd. This is because nationhood has become our widespread cultural norm to the point we can rarely even entertain the notion of an alternative or a time before or after nation states.
I'm not endorsing this argument one way or another, just saying that hierarchies as they exist now are not inevitable, and the act of presuming that there is no alternative is an act of lack of imagination.