My irritant with Tailsa's foreigness wasn't the casting (I was excited for Oona what she was announced), because Jeyne was implied as half Bravosi or something, I can't recall exactly, but that they changed her name and made her ~exotic~ to lure Robb from his duty. They made such a big deal about it (which I think they do in the show for everyone that's not Westeros white so far).