All questions regarding mapmaking for Heroes of Might and Magic 3: The Shadow of Death.

That's an interesting question. Regardless of what anyone thinks, the best approach is to test it in practice. I know that global events are configured to target specific players, and you can choose whether they affect human players or AI players. I just checked in the editor: the properties of the event are the same for a global event, a timer event, and a city event. It seems to me that the event will affect a player after capturing a city if they are checked in the event properties. At least, when I captured enemy cities, various events occurred in them afterward: buildings were constructed, troops arrived...