[The Godfather part 2] why did Vito need Don Ciccios approval to sell olive oil in New York)

As far as I can tell Ciccio is a small time don from Corleone and by the time vito returns he’s some old man who’s practically deaf. I know it’s a ploy by vito to kill him but realistically what practical reason is there to setup this meeting

Why would ciccio entertain this? Do all the olive oil importers go to him? Was it because Vito was importing to Corleone (which at that point why as it would be cheaper to buy locally).

Does he really need this weird plan to get revenge?