Word meaning "assigning appropriate jobs to people" in an organization?

Since the asker seems to be highly skilled in linguistics, the words I proffer might not interest him. But it can be useful for some others.

  1. When an employer wants to assign appropriate people to the duties they would be good at, he should sift out "ashes from cinders".
    Why not use "sift out"?

  2. Every employer shall see about interviewing or testing candidates so as to separate them according to their skills, personality, aptitudes, etc. In other words: "He shall see about the initial screening of candidates for the job. Why not use "screen"?