In regards to nightfalls I run them solo every week just because it's actually easier that way because of how it scales with the number of players. Anyways I always just find a good spot to hide and patiently pick off all the enemies while taking little to no fire... But is that really an exploit? I mean in what war, fictional or non fictional, would anybody think it's a good idea to run around the middle of a battlefield jumping and trying to dodge bullets?