The whole point of AH is to be different, to define a potential question and then work out a way for it to have possibly come about
I was thinking about this earlier today, and wondered what would have happened if Vittorio Veneto had gone the other way ? The Habsburg armies would have remained, but the Germans had basically lost on the Western Front and were beginning to be pushed back by tactics they had little answer for, and from Palestine and Salonika thrusts were being made into the underbellies of the other Central Powers allies.
So, what if Austria-Hungary CAN knock Italy out, hold onto Trieste, but eventually collapses internally through a combination of nationalism, imminent defeat for Germany and Allied armies coming up from the South ?
Best Regards
Grey Wolf