Luck isn't my favorite way to approach it. The biggest wall for me in the game was going from level 29 to 30; not discriminating just being real. I've made it through the entire Hard Raid with 2 30's and 4 29's up to Atheon, but that fight requires level 30 for almost all members. In my experience as both a 29 and in a group with 29's at Atheon the 29's just don't have the damage output in the necessary time to kill the oracles before being overwhelmed. When I was 29 with a maxed Corrective Measure, it would take half of my 100 clip to take one out, less with the armor piercing option selected but that required reloads. Either way you get expunged. My maxed VoC at 29 also took too long to kill an Oracle. If you have 2 29's in the group, then there is a chance that a 30 and 2 29's will teleport and that has a big chance to wipe.
Edit: just to clarify I do run hard raids with 29's, I just don't expect to finish Atheon. I sit on 3 Hard checkpoints each week as a result, I would like to start completing them now that more are beginning to hit the level cap.
Same as GAF