Even Ordenstaat stayed alive for a pathetic amount of time, and they at one point even had more nobles than peasants, in their last region, which was a city.
But my prediction will remain that Asylon will likely never get a secure hold of Koshtlom, and Barca will probably never get a secure hold on Twainville. Aurvandil has some hope in that they have a fairly good position on the peninsula, but Madina is breathing down their south. Madina as well might never regain the capacity to populate the entire big southern island.
I may sound pessimistic here, but the trend really doesn't help matters, nor does history of most realms. Asylon has had the longest among the current "new" realms to attract nobles. It has 10. All other realms can sort of be explained, and Barca is at 10 nobles in a short time, though I think they have one new character made after the initial colonization waves from Terran. It's an adventurer.
Do really prove me wrong though. I'd like to be pleasantly surprised to see Asylon secure Koshtlom, and Barca occupy the forest duchies. I'd like to see Aurvandil spread across the southwest peninsula, and D'Hara occupy the middle islands fully.