Since me and 3 of my friends just achieved Flawless Raider a couple of days ago I decided to write a guide about the subject. I recommend having 4-5 members since this makes it so less people can screw up or experiencing a bs death (+ as we all know you also need some decent players :P). You should also attempt this on Crota's End not VoG since CE is way shorter than VoG (also a bit easier) it allows you to get way more attempts at getting the achievement.