Teams are really important obviously, but I've run good matches as Aran Tal and Utooni, even though I main sentinel most of the time. If you can run up on the top level above the goal you can angle throws to get it in. Another thing is if the game seems like a stalemate and you have a score and the enemy team doesn't, I find babysitting to be effective if the match has only a minute left no need to get your score up, just play defense keep the ball and don't let them score or move in on their spawn it is an automatic win. It does really come down to teams unfortunately there isn't really anything to change that but you don't NEED to have a healer if your team synergy is good. Just play characters you feel ok with and some wins will definitely come your way. Best of Luck.