Do I miss something? Isn't BA doing the same thing: replacing 757 with A320s...
The rationel is : Yield ie less cost (because of smaller more efficient aircraft) more frequencies if possible gives better paying passengers! Thus more money.
If I follow your rationel that bigger is better than Ezy should also fly A320s instead of A319s...
Bigger only works if the volume is right.. that is at BMI, BA, heck at all airlines!
Regarding the internal issue I have no clue
