Why would you actually need duplicate functions? That doesn‘t sound that great. What‘s the exact use case you have? Just curious :)
I'm making a point-and-click adventure game with lots of layouts (scenes) and hundreds of different items. There is a single MAIN event sheet included into all layout event sheets, which handles all the core mechanics in the game - clicking items, dragging items, combining, destroying, gestures, tasks etc. So far so good, right?
But sometimes I need to run custom events and actions, for example, in "Save the princess" scene when a sword is dropped on a dragon I want to spawn blood particles. I can't do this in the MAIN sheet, obviously. That's why I am calling a function "Item_Arrived" from the MAIN event sheet whenever any object on the scene has arrived to its destination. And I have duplicates of "Item_Arrived" function in every small event sheet for every scene.
So in the princess scene inside this function I can check if the item_code=sword and spawn blood. In another scene in the same function I can do something else.
I have several such functions ("Item_Clicked", "Item_Arrived", "Task_Completed" etc.), with duplicates for every scene.
If I had to create the same system with new functions, I would either have to make a very complex function map, or use a huge single function with hundreds of sub-events.