Kudos all. @BBP, I think allowing yourself to choke/not choke the AI is a bigger deal than emperor vs. immortal. (made a similar comment in the Always War SG I think kossin and you played in). The AI is bad at traditional war where the human takes cities, but even worse at handling chokes, and the bug where they don't realize Woodsman/guerilla units get extra moves and steal workers left and right is even worse.
Perhaps another form of this variant would outlaw chokes, and put in an exception to attacking/capturing cities - you may attack a city only to help capitulate if the AI doesn't send out a stack for you to kill, and must liberate it back to your vassal once they surrender?