If you divide the company into 30 fixed groups of people and then each group appoints a representative to the other groups, you've just created a hierarchy. If you want to avoid hierarchy at all costs, that means not allowing any one member in the group to be the leader or the representative to the other groups. I don't see how that's even possible, given that in almost every group of human beings you're going to have someone who wants to take charge.
What if the (rotating) role of representative is explicitly of lower status, lower authority, than the other people in the group? Not leader; lower-status representative. Administrative servant to the group.
That's basically what my team's administrator does; in the old days the role would have been called "secretary". He doesn't seem to be living through a "hell on earth" and has a cheerful, chirpy demeanor, but I'll double-check tomorrow that he's not about to top himself.
One option is, instead of a single representative communicating with all of the other groups, a group can appoint a different ambassador for dealing with each of the other groups. Most people then will have both their normal job and also be responsible for one inter-group communication channel, jointly with their counterpart from the other group. I imagine this sort of a structure would have plenty of its own faults and idiosyncrasies, though.
Perhaps the right answer is to have those 30 groups each with equal say in the direction of the company and within each of those groups the the structure is flat.
It's impossible to have zero hierarchy in a group of human beings. It is, however, possible to have an illegible hierarchy within a group of humans, one only available to the most socially perceptive and/or sociopathic.
