Role Skills a Mistake?

[Shurrikhan]

You can't say "Foresight is overpowered on PLD but work as intended on DRK and WAR".

You easily can though, so long as Foresight plays towards a particular synergy with PLD that it does not DRK and WAR. If PLD were to take on a skill that gives a portion of its Defense as barrier and another portion of Defense as flat damage reduction, suddenly Foresight would be far more worthwhile, an obligatory prep skill for the other. The situations in which that would be significant may still be relatively niche as not to make PLD stand out from the other tanks in itself, but the contribution of Foresight would obviously be inflated for PLD and PLD only. However, the complaint is unlikely then to come from DRKs or WARs, but rather PLDs themselves who feel that their own tool now requires, more than any other slot choice, an otherwise lackluster skill from another class / the general tank skill pool.

You can look at it that way : Skull Sunder and Savage Blade are exactly the same. But, when using Defiance or Deliverance, suddenly, Skull Sunder has an additional effect upon Savage Blade.
So, even with the same skill you could make the three tanks a little different if you want.

And this is what I'd like to see more of, especially playing upon what already appears (via their animations) to be the obvious differences between the skills. Savage Blade, for instance, looks to me to be a counter-attack of sorts, as when dipping under an enemy's attack, while Skull Sunder looks like it'd be strong enough to drive someone headfirst into the ground from the sheer force applied to the crown and back of their head, while Spinning Slash looks like a hell of a cleave, yet no such difference actually exists. Granted, allowing for those differences in a way that would look natural and feel intuitive would first require three significant changes — that their is a means of counter-attacks outside mere procs and unlocks (e.g. target-specific bonus windows), a means for suppression by damage, and that AoEs and STs are more woven together (whatever looks like a cleave, is a cleave; meanwhile, traditionally AoE abilities now have a bit broader, albeit situational, use).

I think development of, say, those three systems would a worthwhile investment, given how much more each of those things could do for the game—as far as I can predict—but I doubt SE would see it the same way. The majority of complexity we're likely to see would seem more likely to come instead from bloated tooltips, or be neglected or even trimmed altogether, rather than from any universal undermechanics.