This is a key point to debunk. It's the mistake Mythic made and it's why every single one of their hybrid classes has failed.If you can tank like a tank, do dmg like a support dmg class and heal like a backline healer you are to strong.
This game rewards you for being one thing. It rewards you for being a strong DPS, or a strong tank, or a strong healer. This disadvantage must be made up for by a hybrid class in it contributing more than average in both of its aspects. However, instead, the hybrid class is punished.
Let me explain what I mean.
Let us assume attack damage scales linearly with some attacking stat A and healing scales with some healing stat H. We'll set the time of the engagement to 1 for simplicity, so we can eliminate it from the formula. For the purposes of this demonstration, we assume that damage and heals have equal value. Each class has the same number of stat points in which to put into attacking or healing, to replicate WAR's MAD problems.
Pure DPS output over the course of a battle in which it only does damage: A (all points in attack)
Pure healer output over the course of a battle in which it only heals: H (all points in healing)
50/50 hybrid class over the course of a battle: (A/2)/2 + (H/2)/2 (half points in each)
The relative contribution of the classes to the battle:
Pure DPS: 100%
Pure healer: 100%
Hybrid class: 50%.
The hybrid class will ALWAYS underperform unless it has the same values for A and H that the pure DPS and the pure healer do.
The other problem is that a proper hybrid class is split between dealing damage and healing, with this split being enforced by a mechanic which penalizes using one side for too long. This means that the class can never be the pure healbot or pure DPS that is favoured by the game. This justifies making hybrids grant a greater OVERALL contribution to the battle to excuse their lack of targeted proficiency in one of the two archetypes that is so valuable. Therefore, proper values of A and H for a true hybrid class with the relevant safeguards are HIGHER than the values of A and H required by a pure DPS or healing class, unless the game in question places mechanical value on a hybrid class, which WAR does not.
This is why it is not, in any way, a flaw for a hybrid class to be rendered immune to the effects of MAD AS LONG AS that hybrid class has other mechanics to enforce that it be played as a hybrid, which melee WP and DoK do. They do not have the tools to be anything more than a support DPS, and they cannot power their heals without attacking.
I'm aware that lifetaps are something of an exception to this rule, because they perform both roles at once. I believe this to be adequately compensated for already by the risk of using them.