Succession wars where extremely common in the mughal and persian empires and I don't think anybody would argue that they where tribal (or rather, they did start out that way but their respective states where not tribal in the eu3 sense later on). In the mughal empire atleast the oldest sons as a rule would revolt against their father when he was getting old and fight him, as well as eachother for the throne.
Foreign inheritances however seem extremely unlikely for the eastern monarchies as they often had 60 - 80 sons with their many wives. There where plenty of successors, they almost allways fought eachother (and their fathers) for the throne however.
If the above empires aren't tribal in eu3 I don't see why the mamluks should be (and if they are then atleast they shouldn't get the horde version of tribalism as they where not bent on expansion but rather the control of the trade flow). This control was in fact the very thing the existence of their state rested on.
Ideally I would love for internal succession struggles to be more common in muslim and hindu empires however and for foreign inheritances to be much less likely.
