Two quick points:
1. My own thinking is that the mediation and arbitration committees should be given the prerogative to organize their own work according to the results of an internal vote, subject to my review especially at first. And I can tell you that the primary goal of my review of whatever process is chosen will be to push for simplicity and transparency without an excess of a priori agonizing over weird problems that might not happen.
2. I also think that at first, each committee will consist of 11-15 people and that rather than appointing specific people to mediate or arbitrate specific cases, we can just be more free-flowing than that. With arbitration, where actual votes on judicial outcomes will be likely, is strikes me that 'en banc' hearings are going to be best at first, with '3 judge panels' being appointed later on if the caseload actually demands it.
My thinking is that we will have a quorum requirement (to account for the fact that people go on vacation or have periods of inattention) on votes, but that all arbitrators will vote on all cases when possible.
--Jimbo