"Not marching in lockstep, but working in an ecological manner where every part is mutually supportive."
As you observe, horizontalism is not a purpose unto itself. It's function is to support the mutual development of individual authenticity. We need authentically autonomous, fully developed, individuals who can work together to figure things out with other fully developed individuals. Practically speaking this amounts to how, though the GA process IS fundamentally useful to everyone, it should not be mechanical and, thus, become oppressive. It should be intimately and fully engaged in the individuals AND the group.
A talented and very young facilitator out of the Tulsa Occupy and I had this conversation and what he said amounted to freeing the process APPROPRIATELY from itself with valid forms of verticality that, because of their horizontal validity, i.e. relationship to horizontal events, are really more like effective punctuation that integrates aspects of the horizontality and then releases that verticality to let the group own it or not as it decides.
I like this idea, because it says that while we are freeing ourselves to be horizontal, horizontality also will NOT be the oppressor; we ARE free to be validly/honestly vertical too; to be either, both or neither is to be free and that is constructive because tasks then become to be more about individual honesty and, hence, validity, and thus also, about RELATIONSHIPS, rather than preconceived ideologies/power-struggles.
A couple of the Tulsa occupiers mentioned that they had really awesome GA facilitation trainings, so I encouraged them to offer their services to other Occupies. I hope their young ladies will also step forward to be part of this if they do.