It's easy enough to snipe Oracles and cheese the Templar, but Gatekeeper can be a pain. Experience is important but also so is having good kit. Having a couple of people with Gjallarhorns can make all the difference at the gatekeeper, regardless whether they are Lvl 29 or 30. Lvl 29s can also struggle with Atheon, as they are often unable to do enough damage to the Minotaur etc if they grab the relic. Even worse are those players who refuse to pick up the relic full stop, claiming they don't know how to use it, as you can guarantee those will be the people sent through. Having a full team of experienced lvl 30s can make a massive difference and I've been in too many games where Lvl 29 have struggled big time at Gatekeeper and/or Atheon, causing the whole team to fail. Ideally try and get into a team of 4 Lvl 30s and 2 lvl 29s and you should be able to get through ok. Given that iron banner was running last week, giving you the opportunity to get lvl. 30 Gauntlets and Leg Armour, there should be a lot more lvl 30 players around to make the job easier.