Events aren't too difficult to transfer over in theory.
All of the commands and triggers remain the same between the two; I believe AoD has some of the new ones (which are probably in Arma as well) regarding tech team skills and possibly retooling.
-Events are placed in db/events folder (you'll need to check with the mod to know which ones).
-Some mods put the text for events in event_text.csv in the config folder (this is the only way to make them multilingual or to override text length limitations).
-The events need to be included by adding them to events.txt in the db folder.
-Event graphics are placed in the gfx/event_pics folder.
Aside from actually getting the events in there, there are a few other reasons mods may run into trouble:
Many rebalance manpower or resources through events, but may also make drastic changes to the provinces.csv in the db folder (it tells the game what resources and buildings to give each province).
Many add tech teams, leaders and additional countries in custom tags. Events that use these resources may not fire, crash or malfunction in some other way.
Some may rely on customized AI files; adding events from those mods may drastically impact the operational capacity for the AI.
Events between mods may have conflicting event ID numbers, which would require some editing (but this is true of combining HOI2 mods, anyway). I'm not aware of any events that AoD specifically adds, although I'm sure there's at least one.
Overall, simple events are very easy to import. Copy-pasting the event text and a picture and editing one file could get them working.
Game overhauls will be more difficult; they won't take into account AoD's functionality changes (retooling; naval brigades; individual unit supplies; IC changes from infrastructure and concentration; etc.).
