agree with ya right there mate, I've just been through match on that one mission with the baby barges. we had three tier ones (including me) and one no-tier (who's playing Alicia) and we were able to relatively easily go through the match while keeping the no-tier alive (who doesn't even realize shes using a shotgun and keeps shooting from far away)
but every single time we had to cross over to the next barge, the no-tier just refuses to get on the platform even when all of us are are spamming the "get over here" ping the person continued to try and fight off the wardogs everytime. we repeated this process for the next three barges until they just left on the final bit of the mission. makes me wonder if they just skip the tutorial videos and thought they can just learn it on their own.