I'm reading Runciman's history of the Crusades and have noticed how the Crusader states leaders are chopping and changing roles, responsibilities and loyalties.
Would it be possible for out of these constant changes the Kingdom, Principality and 2 Counties to merge into a smaller number of larger states? IIRC at one stage the ruler of Antioch was regent for Edessa, perhaps this could become permanent. Or perhaps Antioch could absorb a large chunk of Edessa during the fighting which extinguished that County. I don't know, just thowing it out there.
BTW I am only up to 1110 so lets not say what happened in the 1200s, I'm talking about when these states were at their largest.