Are all the Tanks identical?

[CKNovel]

They share a lot of similitudes but they also have their fair share of differences.
To say some feels similar, I can agree. To say they're all identical, that's hyperbolic.

Rotation wise
WAR and DRK will share the same problems when mapping their rotation, except DRK has mana on top of it while WAR will be hardly punished.
PLD will have its own problems to tackle.
GNB will have completely different problems.

DRK is basically an extension of WAR with two or three different things, it's basically the biggest culprit in the "all tanks are similar" debate.

Mitigation wise, it is also different.
GNB will have camouflage being very good against auto-attacks.
DRK will have Dark Mind, short cooldown extremely good against magical tank buster.
PLD is the only tank with 2 raidwide and able to shield itself and its cotank at the same time.
WAR has the amazing holmgang and self-healing capabilities but its unique 90 has no mitigation tied to it unlike Dark Mind or Bulwark.

They have the same base, but to say they're all copy pasted is a massive stretch.
Most houses are rectangular, all of them have a window and a door. It doesn't mean they're all similar.
But it's true they share too much similarities.