Toirneach Lann:
Lann takes the rear guard and climbs last.
Ok so this is my suggested approach to the situation:
Stealth force scales the cliff and invades from inside the enemy camp.
Dann, Brannon, Griff, Drake, Jon, Aphail(noncombatant).
Main assault force approaching by the stairway from the front.
Chlainn, Usopi, Lann, Lute.
IMHO, if Lann climbs with the Stealth force, the main assault force would be too small. Also, Lann is wearing heavy armor (chainmail) right? More suited to go from front than to sneak around...:)