If SNN had had a bunch of commuter a/c stationed there operating to IOM/BFS/LDY/UK west coast maybe UK feed would have been better - but it would have needed real hard selling on the part of EI in those UK ports. It would have taken someone of O'Ceidigh's chutzpah to pull it off.
As it is you could now have Malev feeding traffic to American through DUB and EI getting none of it because of their exit of Oneworld.