Why would I spend 50 DE for ONE dark troop with 8 DPS and 80 HP that negates walls when I can spend 30 DE for THREE Minions with combined 150 (50 per) DPS and 234 (78 per) HP that also negates walls?
Because these are better at pricking off buildings becuase archer towers and cannons can not atk it without it alerting it's presence (atking it)