Thanks to Joel Garver for this reference: Charles Hodge points out that LC 158 claims that only those who are “sufficiently gifted, and also duly approved and called to that office” may preach. The requirements for sacramental presidency and preaching thus appear to be the same. And if there are exceptions to the requirement that ordained men preach, then it might be within Confessional bounds to say that unordained men may preside at the sacraments.