Shatter is quite viable if people understand and perform a given function:
Tanks: Harrass, stun, and shut down enemy ranged/healers, support melee/ranged bursts on players, cover/defend teammates under attack.
Healers: Eyes open for team/alliance members being focused/debuffed and heal them. In downtime, heal and shield the team.
Melee: Main attack on players/ice. Always keep your eyes open for soft targets (50% HP or less) and be ready to switch and secure the kill.
Casters (Specifically): Attack/debuff enemies, especially at ice spawns. Ice is 50% more resistant to magic, so focus players instead. Take advantage of grouped up players.
Ranged Physical: Same as Melees. Eyes open for incoming threats. Play as your team's "Anti-caster", and actively go after priority targets (that can be ice, healers, Battle Highs/Fevers, or anyone who goes in too deep/is trying to escape.
Important QoLs:
- Getting hit while riding on a mount applies a heavy debuff to you. You can also be stunned or slept and this makes you, more often than not, a free kill. Get off mounts near enemies. Even if you just got your Demonic Lanner/Firebird/etc. The same rules apply. Also, the manacutter moves slower on land, and no, you can't fly. Get off mounts near enemies.
- All 3 Dex jobs have a skill to reveal hiding NINs. Utilize them if you find your base frequently being taken behind your back or players surprise attacked at your spawn.
- Battle Highs or Battle Fevers are players with a killstreak buff. Treat them as a high threat and focus them. They will usually have a healer focused on keeping them alive, so if you encounter one, look for a healer close by as well, and move to suppress both.
- Though longer, there is a safe path around from each base to the north, southeast, and southwest ice spawns. Unless you want healers working overtime (and possibly having MP issues), never drop off a cliff to the ice when other teams are already there. You'll only be a half dead target to finish off, and likely end up with no points from the ice.
- Healers cannot use Cleric Stance, and ice is 50% more resistant to magic damage. Don't attack ice. Tend to your team.
- Sometimes (and lately more frequently), all small ice nodes activate at once. Start attacking the ones further out from your base first or your enemy will.
- (Additional Edit) Healers, do not use your standard Raise/Resurrection in PvP. There is a PvP Raise, Divine Breath, which is instant and does not give the weakness debuff. Raising someone with weakness all but guarantees you'll lose points from them dying a second time right away.