There appears to be a fault in the Non-Christian carve-up on death of ruler events, they don't seem to fire for sheikdoms/chiefdoms , and hence sheikdoms, which should be ideally one-province local tribal leaders, are allowed to grow to monsterous sizes while the rather modest kingdoms are carved up among many heirs. Any Muslim realm which is over the allowed provinces, should quickly be carved up among the heirs to the ruling monarch, including sheikdoms.
I also think that Muslims should also, through events be able to create higher titles as soon as they occupy the required provinces, so if the a Sheik took the all the base provinces of the Emirate of Granada, than that sheik should automaticly assume that title, becoming that realm. This would allow, upon the death of that emir, the new emir to have his reletives as his vassal sheiks, allowing low-ranking Muslims to fight their way to the top. Even better have the claimable titles change according to era, so the Almohads and Mamalukes for instance have a chance of appearing mid-game.
I also think that Muslims should also, through events be able to create higher titles as soon as they occupy the required provinces, so if the a Sheik took the all the base provinces of the Emirate of Granada, than that sheik should automaticly assume that title, becoming that realm. This would allow, upon the death of that emir, the new emir to have his reletives as his vassal sheiks, allowing low-ranking Muslims to fight their way to the top. Even better have the claimable titles change according to era, so the Almohads and Mamalukes for instance have a chance of appearing mid-game.