It wouldn't seem unreasonable, but none of the high-ranking Seanchan officers we've seen so far have been property. When Tuon was deciding whether to attack the WT or meet with Rand in tGS, and in later strategy sessions, all the officers were either Low or High Blood. Maybe only High Blood positions are hereditary, then? Meaning that as Low Blood die, the Throne can give their estates to the new up-and-coming talent, while avoiding the ranks of the nobility becoming bloated?



WH, p429, Egeanin - "As a girl she had even dreamed of being the Hand of the Empress at Sea, just like her mother, to stand at the left hand of the Crystal Throne, so'jhin to the Empress herself, might she live forever, allowed to speak directly to her."

As mentioned in other posts though, I'm taking so'jhin to mean simply 'person given leave to speak to/look at the Empress directly' - not being property. I mean, I know rulers have to have keep some distance from their subjects, but not every occasion is a formal one, and even an Empress must sometimes want the odd frank or frivolous conversation over kaf that doesn't need every other sentence translated through a monotone servant.