First of all Shield Fortress is a when maxed 50% dmg reduction for yourself and 25% to all players including yourself so that would leave Knight having 75% dmg Reduction while Healer-like characters could Heal all players including knight.
With the effect of Shield Fortress you could activate before Aura shield too which means a total of 95% dmg reduction and added with power of Aura Armor that dmg reduction would be complete 5%(Havent tested the whole combo tho is true 100% dmg reduction), that skill was the "Omg we're saved from danger skill" which helped a lot in raids. Then comes Aura shield which has 1 min Cooldown while Shield fortress has 2 min cooldown, that means you can spam aura shield all time and you will have a good dmg reduction skill every minute.
But what does warrior has? Warrior has Endure when maxed that gives 40% dmg reduction for 10 seconds with the downside of 2 Min Cooldown and that skill doesn't affect the whole party but only itself for 10 seconds. Then comes Parry which raises the chance of parrying by 40% if maxed and keeping a note that parry effect means % chance to block 50% of the initial dmg, which is the "Spammable" skill with 1 min cooldown. Parry is good no doubt what has a downside of not blocking the entire dmg. So as a result warrior has power to have bigger chance to parry for 10 secs with a 1 min cooldown, and reduce the dmg taken to himself by by max 40% with a 2 minute cooldown.
On the other side Knights have 20% dmg reduction with a 1 min cooldown to himself and a skill that brings 75% dmg reduction and 25% to Party members inside the radius.
As an result to the Defensive side of skills Knights has better defensive utility than warrior and also brings dmg reduction to others, while Warrior doesn't. Only problem is with Shield Fortress that Knights cant do anything else, but the point is that this skill is used in raids that are now useless for ppl.
Now the Recovery part.
This spot i can surely say that Warrior wins this by 100%
Tension Relax = Heal 30% when used and 60% over 30 sec
Aura Heal = If lucky you can heal 2-3k hp xD (For note i haven't tested the power of this but it has been totally weak)
So Knights skill set is more Raid Orientated while Warriors are more like a Replace to knights with a good 1 vs 1 Skill set.
But my point was that people doesn't do much raids cause of the AWESOME defense coming from the BUFFED Dayr Desert Gears/Crafted which made Knights Useless.
So as an result Knights are totally useless cause in this game here isn't anything that would make people want to have Knights as a party/raid member.