[john-radio]

If only there were a word for a level of language proficiency where the person's speech is perfectly intelligible, but where there are still audible clues about the person's linguistic background that could be used to discriminate against them, and if only this weren't a "hypothetical person" but OP said they were talking about strong engineers with mild accents in their very first post? To act like the candidates' english is too poor for them to be employable is being willfully obtuse at best and outright racist at worst. There's nothing particularly difficult about working with someone who has a bit of a lilt or a twang or what have you; in fact it is more fun than working at a workplace where everyone sounds the same.