The situation for CO is somehow more complex. First of all, I like to see real numbers for the 752`s operating across the pond. A somehow halfway talented Controller can make every flight look profitable, if he just plays a little bit with the cost and revenue allocation, especially for connecting passengers….
The leasing companies certainly agreed to CO`s plans, it basically gave the 752`s a few more years of operation instead of seeing them getting a lot of sun exposure in the desert.
757's use significantly less fuel than the 762, while having nearly identical pax capacity. When fuel is $$$, that is making a huge difference in operating cost. 762's do have a bit more cargo capacity, but not *that* much.