Im not sure about you two but all four tanks are in solid positions. But if changes needed to happen...

PLD - replace Guardian (Cover) with Intervention to promote more active and preemptive mitigation play. This will indirectly buff Paladin as they will get.to Guard for themselves more.

Would benefit from slightly stronger Atonements (10k maybe) or Confiteor granting 2x Holy Spirit stacks for 10000 dmg

WAR - replace the 10% HP shield on Bloodwhetting with -10% damage taken. PLD has 15%, DRK and GNB-tank have 20%, all with about 50% maximum uptime. In all other parts WAR is good.

GNB - ability to draw & junction teammates to ensure at least access to tank junction + giving Aurora a +10% damage dealt effect for 10s on target to cement Healer GNB as a support-hybrid similar to Sage.