[Edi]

1) No. You need to clear the whole lineup with #clearrec, then rebuild it.

2) Confusing user interfaces generally irritate people. So I suggest you just clear the lists, because all you need is several #addrecunit <monster nbr> commands in a row for the units and #addreccom <monster nbr> for commanders. Not hard to do. That way you can also decide the order in which the units appear in the recruitment screen.