my take is that i think it depends on the situation, but with that many people, coordination can definitely get pretty chaotic if there are no structures. but structures don’t have to be hierarchical.

anarchists have the concept of a mandated delegate. someone who people pic to execute a task. this role is usually recallable and can be questioned. it’s limited in time, and there are strict definitions of what the task is, and what actions are permitted to execute it. any power over others is limited to people agreeing to give that power.

this can be something as basic, as cooking dinner for a group, were the group might decide some criterias for the food together, such as ingredients to avoid, servings, and budget, and then pick a person to cook the food.

this same model can be used for federation and coordination. a small group of people, in a bigger group of people, can come to a decision on a topic through discussion among each other. then they can delegate someone to represent their decision in a meeting of delegates of all the subgroups. those delegates can then discuss among each other and make a proposal for a decision. now these delegates typically do not just have the authority to just accept any decisions for their subgroups. part of their mandate may be, to accept specific decisions, that the subgroup agreed to in advance, but for many proposals, they would instead first inform their subgroup and then have the decision made by the subgroup. the delegate does not rule and is instead, in their role as a delegate, ruled by the group (that includes themselves).

similarly someone can be delegated to the coordination of a task. they would be mandated to coordinate toward an end decided by the people and as part of their mandate they might be allowed to tell people what work they should do, in order to reach the goal. but those people do not have to do as the coordinater tell them to. if they disagree with decisions, they can together with the rest of the group alter the mandate or recall the delegate and pick someone new or even work without coordinator for a time.

of course hierarchies can still form in this situation. it is important to have a culture of critical self reflection, so building hierarchies are noticed early and can be worked against. something that definietly helps is the value of free association. as long as we try to enable everyone and every group to associate and disassociate with and from each other as they like, it is hard to force anyone to do or support things they strongly disagree with.