RE: Southwest. There isn't the same overcapacity problem in the states. In fact they have experienced consolidation in recent years.
But that wasn't the point being questioned.
The point made was that after 200 aircraft economy of scale tails off....
I have not seen any study that backs this up. Therefore I am assumming poster either has details of such studies or has made up a number that suits because it is close to Easyjets fleet numbers.