Are you on Perospero's side or Daifuku's side on this hypothetical argument? Obviously, I agree with Daifuku that Katakuri should be the new captain after Big Mom.
You cam't lead the crew if you don't have the right power to do it. A leader aside his leadership(political knowledge) should have the power to change the things which he want(one piece verse).
Having underlings who are stronger then you would only mean that they can change and rule everytime on their own. As I like Perospero as character a lot, as a Captain he neither has the power or the dream to became one.
Katakuri seems having his own dream(freedom for his family) and also enough strenght/power(strongest Big mom pirate after BM) to change things.
Adding to the points, Katakuri gonna comeback later in both strenght and new knowledge about the world, as the battle push enough Luffy, Katakuri too had a extrem battle and overcome on his own limit. He will be for sure now stronger then before he facing Luffy.