Also, it wasn't necessarily a purposeful thing. It was just happened that way. After Hireshmont gave up the Chief Magistracy his many connections and positions, and the fact that he was a very active, just meant that he was de facto the voice of Terran abroad and no succeeding Chief Magistrate had much hope of being able to bring that much diplomatic clout to the table.
It was not at all intentional.
Hireshmont actually, every new ruler, would give them briefings on every other ruler, their personal history, who he knew in those realms, what past deals/relationships had been struck, etc, etc. And he would actively help the various rulers with their pet projects (they all had some).
He also tried to get them all to convert to Astroism so they could be something other than diplomatic non-entities. Most didn't take him up on that offer (though Kas did: and he's done rather better than the other Chief Magistrates).
Hireshmont would have been happy to stay ruler for a long time, but after various internal squabbles (re: Erasmus), that wasn't possible with Terran's internal politics. So he went for the next best option: try to train a successor. Nobody was quite up to it except for people who didn't want it. And the folks he did train well (most promising was a fantastic noble called Fyodor van Kaya, then there was Alura too) for various OOG reasons didn't mostly stick around.
