While browsing through the start dates I noticed this:
Being unaware of the great Bengalese Sultanate of the Andamans, I loaded them up, and was amused to find myself the ruler of a vast kingdom of several hundred subjects, whose number was rapidly decreasing. Eventually, the colony died, putting me in an interesting situation in which I owned literally nothing. No wonder even peasants looked down on me.
And here's some interesting screenshots from my current game as Oman:
Probably the most successful reformation I've ever seen, at least in my own games.
I have no idea how Najd became a horde. However, it led to their continental holdings being colonized by myself, Hedjaz, and Yemen, leaving them only with Bahrain, which I deemed too worthless to take. Despite their size, they'd still declare war on me like clockwork every 5 years, which would always end in either myself or my uber-Yemen vassal beating them back into paying their grand tribute of .3 ducats a month. Not too smart, but you do have to admire their tenacity.
Eventually I got sick of their antics and colonized/released them, getting rid of some worthless desert provinces that they had cores on in the process. Interestingly, they remained steppe nomads even after being released, giving me a steady stream of colonists until I sold the rest of my Arabian holdings to Yemen.