Im just saying, what achieves plot movement more? Shanks vs Blackbeard being a wholly separate event or Luffy being able to interact with both Characters before, during and/or after their fight?
I am absolutely not confident in Oda justifying a huge battle without offscreening much of it, especially we arent meant to see how both characters fight yet. That changes if they ARE involved in a major arc with the main cast. Thats how its always worked.
Personally I dont see how you'd want the former anyway lol, it doesnt actually service any story outside of isolating 2 characters already tied to Luffy for different reasons