Yes a pilot but with a MBA too!!
The problem with your analysis is you are comparing apples to oranges. It is a meaningless comparison. If the extra pax generate extra revenue and at the same time increase incremental costs then it makes no sense. That is why you need to look at fuel/ANM.
The 787-8 will take 250 but then it might not be right for the route structure, while conversly the 330 might take 280 but it it can only fill 220, then it's too much.
Each airline looks at the purchase of new aircraft very differently from the next airline. That's why it's very difficult to make broad sweeping all encompassing remarks.