MThompson016
SOC-12
I think the Subsector or Sector Moot would be a matter of Ducal preference and local tradition. Each will be different, some will be absent. It is, however, a natural outgrowth of the given noble arrangement that the Dukes will call their subordinates to consult en mass periodically.
The idea that a local Moot has the power to elect a Duke is, on the other hand, ridiculous. The Zhodani work that way, but not the Imperium.
I'll disagree here. It allows for the senior viceroys to understand who has actual political leadership and respect from those who matter. A replacement Duke who has the support of the peerage for his area is going to be more effective, and understand the different factions that play in his demesne.
And the one case mentioned in GT JTAS is when a Duke passed with no named heir available. His son was KIA in the Marines (Aslan, you know), and no direct heir was nominated. As a special occurrence, a nomination of an existing member of the Nobility makes a lot of sense. It was also treated a subject to Imperial veto, but that was noted as unlikely.
And that much power and money in one spot is a lucrative ground for morally flexible free-lancers.