I only play SP, almost always EA. I had noticed since I started setting independent starting strength to 9 that frequently in the first 10/15 turns I would get the message that Mictlin was defeated and ceased to exist. A couple of times I was adjacent to a Mictlin province and it would go independent at tis time. I would then find the home castle to be an independent province which meant that Mictlin was not conquered.
So I started to always include Mictlin as an opponent in new games. I find that about 60% of the time Mictlin evaporates in the first 10/15 turns, and once by the 2nd or 3rd turn. I have never seen another opponent evaporate in the early game.
I must conclude that Mictlin always(?) sends its pretender out as a SC in the early game and keeps going to the well no matter how many hit points are left. Has anyone else noticed this and does anyone have an idea why this only happens to Mictlin, or at least only very rarely to other nations?