As I just had to find out, the AI is completely unblamable for Mictlans early dominion death, which occures all to often before turn 10 !!!
To see why, check this screenshot:
Means - your only source of dominion is blood sacrifice.
What gives ONE temple check per slave sacrificed.
Normally, a nation gets dom spread from its prophet, its temple and its home province. I ran a test without prophet, only Dom-5 and capitol and temple therein (imprisoned pretender).
Effect: dom strength went 2,3,3,4 in the next turns.
Mictlan (LA) with a holy-1 priest set to do sacrifice the 1 blood slave the nation gets from its capitol site, the dominion strenght went as follows:
1,1,1,1,1,1
Even if the holy-1 priest or the sacrifice is not bugged, this is considerably unbalanced: To get the same number of checks, Mictlan would need to sacrify 3+ slaves per turn in the capitol alone - using a holy-3 priest and a blood hunter. But in a 'narrow' environment, this takes too long to set up, especially for the AI, what results in unnecessary early dominions death. Not to mention the fact that hunting for 2+ slaves per turn in the capitol will be thoroughly detrimental to your gold income ...
Only when I started to use a holy-2 priest and sacrify 2 slaves per turn, the dom strength started to rise: 1,2,2,2,3 ... .
I doubt, though, that the AI is aware of this - it does as its told, sets a priest to sacrify the 1 slave it gets .. and dies 8 turns later.