Intended, says fallen captain. I'm guessing they did it that way because you'd go through a lot more ammo and it would take a while. I do mine at the entrance to the sky watch from the mothyard. There's a captain and two other little dudes. Sit on the road by the small building towards the water and snipe the captain in the head, one shot will drop him. Then run up and kill the two others with your primary to get more ammo, then run back to the little spot. They'll respawn in about 15 seconds. Repeat 10 times and you're done in about 6 minutes. If you have a hive and precision kill primary just keep going through the building and finish in the sky watch area. Can usually do them all in the cosmodrome unless it's s Vex or cabal week.