I'm not sure if there is a matchmaking system in place and I am sure you guys are trying to pioneer a bunch of things to add to your resume. However, I was recently thinking about the entire situation of grouping with random people. Sometimes I get people who know exactly what they are doing and sometimes its people who are clueless. The gear also varies from people with people having the minimum recommended and some people having quite higher level gear with the purpose of farming the area.
My suggestion is to add a bonus buff/statistic multiplier for players who choose to do random groups not sure how the math side works for the game but I have gotten into countless parties where we die to stupid things, people skip the tutorial, and all sorts of nonsense that ends up wasting peoples time, energy, vials, and health kits. The way this would work is that for every person in the group that wasn't invited and got in randomly there be a 2.5% modifier to all stats. Like I said I don't know the math so the multiplier would have to be small enough to not give too much of an advantage but big enough so that if there is at least 1 or 2 people in the group who know what they are doing they can perhaps carry the group a little longer. This way if you do a group full of people who know what they are doing via friend invite or guild invite who are also likely using voice chat they don't really need any modifier but for the people who have no idea what there doing, have no voice chat, and have mediocre gear they are given a better chance of enjoying the game a little longer which might be long enough to see the games potential.
I know you guys make money off energy and people reviving or whatever but the goal of this suggestion is to increase playtime. You guys were celebrating about having a million accounts or whatever but I wonder how many of them just quit cause the energy interpretation or they got into groups that made them think wow this game is not fun so why would I even pay. When in fact I believe its a really cool game and I had the cash and patience up front to invest to find out that this game isn't bad but with the population fluctuating the way it does due to people not understanding how easy this game is to play casually. It would benefit the community long term I believe to consider this sort of feature.