I am betting that the way forward would be to understand that there are some valid strategies, and then " roll a die" for each AI, and pick one, at a few different points in the game..maybe every following era after DP is discovered. If the strategies given by the table plus the die roll are compatible, then the AIs will form DPs, or ask the player for a DP.
Super challenging though to come up with such a table of valid strategies. It is not anywhere near as simple as what i suggested, either. It will also depend on relative geographic location, and potentially even UA and policy choice. For instance, aztecs and assyrians have to play as sharks ..uh, i was going to say "swim or die" , but really it is about eating. Aztecs need to constantly be killing units, and assyrians need to capture cities. There are other civs in a similar position.
You see the problems, I'm sure. This is too vague to be actionable.