Quote Originally Posted by BabyYoda View Post
40% MT for all tanks
Why not 40% max hp for warrior instead? To enforce identity to the job.
Honestly? Because of scalability. 40% max and current HP is just a (slightly worse, as it can't provide immunity to debuffs it thereby ignores) 40% TBN. Such is better if incoming damage is less than 100% of the tank's normal max HP, worse if it's more. As such, it then becomes better for lower damage densities, worse for greater.

Because casual content tends never to reach such densities, it can basically just be considered altogether and consistently better in said casual content. So then you have a tank or two who are perfectly competitive in the hardest content but then moderately to significantly advantaged in all else. You give anyone else anything to compensate, such as a use case for Clemency or Cover even in a normal composition, and now the difficult content is faintly imbalanced. Because the larger the difference in scaling factors, the less possible it is to balance sustain for both the most intensive and least intensive content. Or, again, for fights differing in bursty vs. sustained damage.

It's not impossible to balance things despite that, but it requires either greater consistency in fight design and/or some definite ingenuity.

Oddly enough, though, probably the best way to deal with disparity between analogs... is to not have any direct analogs, and allow for more frequent and granular layering of defensives, all of which tends to allow jobs to be more distinct. You just can't balance things so tightly while manning only small variations on ~6 otherwise identical levers.