I killed camp15 in 2 weaves: Fisrt, I sacraficed 155B, killing the shadowsneakers and the firedancers (they also killed 4 dervishes), then I sent 200LB to kill the dervishes, all 200LB survived, because dervishes are last strike units (in theory, 160LB is enough). This setup may be suitable for players between lvl 30-35, without veteran generals, and for those, who don't want to use so many Recruits.