TBH, I think part of it comes from not knowing the people you've grown accustomed to. If I happen to queue with a bunch of people from Adraas, we have a much better time of it than if I happen to be in a group of people I don't know.
I don't know their tendencies, what they are good/bad at, and that brings the skill level down for the entire team, myself included.
Give it a few weeks, a month perhaps and there will be much better cohesion for the pugs.