I'm not sure I buy into the somewhat rose tinted description of EI's northern operations.
In reality they came in and massively misjudged the market, assuming they could smash Easyjet on its own patch. They lost a fortune and hastily started experimenting with routes before retreating to BHD following a large spat with BFS.
In 10 years they have reduced to 1 airframe doing 1 route, have no based pilots and a handful of cabin crew. It's good they run the LHR because frankly BA are bleeding us all dry on it but let's not dress it up as a great success. Their LGW base was a similar story but now totally extinct.