Archers might intially be well be placed on both ends of the lines of infantry Nogrod mentions. There they would be free to shoot in order to offer at least some protection to the infantry or cavalry as they round the end of the tunnel, as well at at the victims of the trap. Of course, the wind would present a major problem, and the lack of numbers following Athwen could clue them in that something else might be in the works.
While Carl might prove a crack bowman, I don't know about his accepting a formal leadship role, Child. Unless, of course, it was thrust upon him.
Nogrod, Folwren's post has mentioned some of the slavers reaching the tunnel already. I am wondering if the goodguys on horseback might go in pursuit of the rest of the slavers.
E-gads! We have 1 of the fellowship buried and 1 caught by a slaver. Things are not looking good at this point are they?