(I know this'll bloat my post count a little, but I think putting it in a separate post may be better for it.)
I think I may have worked out how the Who and Whom columns work. If you choose either of those columns, the members' names are ordered by join date, in the same manner as the When column (i.e. latest to earliest for descending, vice versa for ascending). So, if you're looking for a specific member, you need to know their join date. This (sadly) means keeping the Members list in a separate window, to check on join dates for members that appear.
It's a messy way of doing it, but it works.