It would make Eric so much more interesting if he had developed feelings for that girl while in Somalia, but had to reject her because of his relationship with Ash, only to lose her (when the news announced that everyone was killed, I don't see her making out alive unless she was taken to be raped and Eric had to save her). The amount of stress he'd have to endure to not only survive, but deal with guilt and loss... He'd look like a very mature character. Instead, he's just the accommodating boyfriend who has no personality or interests other than Ashley herself.