First of all you can't 3 man VoG(without glitches) you need at least 4 people and most people need at least 5. No matter what, there is a difficulty in completing them, and whatever you get you earned, but let's say the ones that drop from enemies(legendary engrams) are not earned, but if you get something from the stages in VoG then you earned it, except Crota, he is too easy.