Trials is often dominated by snipers because of how good they are at shutting down revives. That being said, teams with good shotgunners are more likely to win. The highest level of play is sweats or scrims as some say. Most often you'll see a team of 2 warlocks & 1 hunter, where 2 are using shotties & 1 is sniping. Voidwalker, storm, nighstalker, & blade are really all anyone uses. Then for primaries you'll see eyasluna, tlw, or thorn. Not many other primaries are used unless it's a god roll hc or pulse.