As a provisional suggestion, I'd like to offer this: For event E specific to an Alternate Universe AUa, we'd create a page AUa.E - for instance, "Denton AU.Invasion of the Falkland Islands" - though it should be noted that "Denton AU" is a placeholder until the parties in the AU can agree a better name.
Makes a lot of sense. This format looks familiar, and would help sorting articles per AU first and prevent mix-ups.
Great care would have to be given to the consistency of the AU naming across articles.
_________________Soviet Century/Cold War 2020 Alternate Universe
: Soviet and other Cold War designs 1990-2020.