I love many of the concepts of "sociocracy". That said all this conversation about hierarchy and power just gets in the way for me of unlocking the potential of the process and the people in it.
Could we simplify thing a bit by asking and answering
What is our shared or common purpose?
What is each person's "investment in" or how much do I care or commit to that purpose?
What is the system of performance and accountability that we will operate in order to achieve our purpose?
The role of all the team members is to "manage meaning" ( Why are we here"?) and maximize connection ( How are we here together).