There is two ways for SE to implement job identity changes for tanks,
1- go all in with homogenization.
2- doing overhaul tank rework: Each tank have positives and negatives.
Most likely it is the first one but they could do overhaul to give tanks more uniqueness.. if this happens what do you suggestion? Let's brainstorm
To me I could summarize it as following:
To clarify more all tanks have can apply in any fight and there should be no differences between them all can go MT and OT for all content.
1- Paladin
Positives: highest defense and passive parry rate, high speed(low GCD 2.0) attacks, party healing.
Negative: less self healing compare to other tanks.
2- warrior:
Positives: highest max health and Hp regen, slow but heavy attacks (2.5 GCD)
Negatives: less defense compare to other tanks and no shields (similar to white mage that they have almost no shields)
3- dark knight:
Positives: highest shields in the game with high self healing( example: if 50% of shield break heal for the shielded amount), slow but heavy attacks (2.5 GCD).
Negatives: less defense(similar to warrior), less hp pool (similar to paladin), healing amount have cap with MP consumption, using too many healing skills will reduce overall DPS.
4- Gunbreaker:
Positives: highest passive parry rate and ability to have active parry skills(if successful apply self shield) and continuation convert shield to heal similar to samurai third eye, fast based job similar to paladin(2.0 GCD).
Negatives: defense lower compare to other tanks(similar to warrior), hp pool low(similar to paladin), job is focused more into active parry.
Rework to 1 min cooldowns and removing invisibility:
Warrior Inner Release: Each GCD will consume 15% of hp prevent hp to go below 1 hp and damage increase effect duration is 12 second.
Paladin Requiescat: apply invisible after Requiescat but have a condition that if Paladin hit a non magical attack it will break the effect (magical attack will consume mp) duration 12 second.
Dark Knight Delirium: reduce mana consumption to 0 for all cooldowns and double the shield and healing amount(TBN) and apply resistance from slash attacks and each OGCD will apply shield, if hp reach to 0 dark can die while in the effect, duration is 12 second.
Gunbreaker Superbolide: reduce hp to 1 and prevent from dying, passive parry percentage increase, get full 3 stacks of Cartridges, active parry will double the shield and continuation heals the shield amount , duration is 6 seconds can increase after each successful active parry by 3 second max of 12 second.
I am thinking loud here, I am not a game designer I am just a player after all.
What I write is what I think would be cool to see in my eyes may people disagree and it is OK to think other wise.
Lets have a fruitful discussion.