It is my understanding that when one is in the year of mourning following the death of certain relatives, he is not allowed to lead ["daven from the amud"] certain prayers (such as those on Shabbos, Yom Tov, Rosh Chodesh and Chol Hamoed).
If so, what would happen if all 10 people gathered to daven are in fact mourners? Would any of them be able to lead the prayers? What would they do?
(of course, correct me if my initial assumption is incorrect)