Ohhh boy... The level of ignorance in your post is reaching critical levels. First off, Ravana speed runs are done with 1 tank, 1 healer, and 6 DPS. Secondly you seem to think that PLD is far ahead of WAR in the mitigation department which is simply not true. You then said that PLD has the superior set of CDs which is again not true. Lets take a look at each defensive kit THE RIGHT WAY
Rampart vs IB: As far as uptime goes they are roughly equal but I will say IB is the winner for the simple fact of accessibility.
Vengence vs Sentinel: If you dont know why Vengence is the superior CD in a prolonged fight by now then you need to stop posting here. But to touch on it briefly, the amount of uptime Vengence provides with its extended duration AND increased DPS for WAR make it superior than a flat 40% mitigation. For example in a five minute fight Vengence would out mitigate Sentinel... By a lot
Raw Intuition vs Bulwark: This depends on the shield equipped and what is being tanked. For multiple massive physical hits then Raw Intuition wins because of reliability. If we are talking about a trash mob then Bulwark might be better. However if you change this to Raw Intuition+Awareness then the amount of uptime RI has minus its one downside makes it the clear cut winner
WAR Convalescence vs PLD Convalescence: Now obviously native spells are superior but really WAR wins here because while it gained Convo from cross class PLD gained.... Uhhh... Mercy Stroke?
Holmgang vs Hallowed Ground: Now obviously Hallowed Ground wins out in the overall mitigation and usability but the uptime of Holmgang allows more more flexible use of WARs other CDs because you can almost guarentee Holmgang will be up for the buster. Just look at A1S as an example. By Holmganging 1st and 3rd i can freely use Vengence for Royal F and will actually increase my overall mitigation.
Clemency vs Equilibrium: Hahahahaha... Yeah Equilibrium wins because Clemecy is too busy eating glue and getting interrupted.
WAR foresight vs PLD forsight: They both suck
WAR Bloodbath vs PLD Bloodbath: WAR actually has a use for bloodbath with their stupid DPS, overpower, IB, and Berskerk... WAR wins by a landslide.
Sheltron vs Thrill of Battle: This is a toss up and depends on how each is being used. ToB is great as a recovery tool after Holmganging or a means to meatshield larger hits when coupled with Convo. Sheltron COULD be amazing if it didnt get taken by an AA half of the time but its MP regen and CD time are great. I say this is a tie.
Storms Path vs RoH: Not even close. Path wins
At the end of the day WAR possess a powerful defensive kit while simultaneously possessing significantly higher DPS than PLD. Hell I didn't even go into the fact that some of WARs CDs also double as offensive tools with stacks or the fact that WARs crazy defensive uptime also allows for them to enter their DPS stance safely more often than PLD without taxing the ever loving shit out of their healers.
When all is said and done PLD only out mitigates WAR by a TINY amount and this only applies to physical heavy fights or fights that have large numbers of trash. If we are talking about magic heavy fights such as A4S then PLD actually mitigates LESS. This isn't even bringing into account that higher DPS = Shorter Fight Time/Pushed Phases = Less Damage Taken. So in those rare case where PLD mitigation does significantly surpass WARs mitigation it does NOT allow for a significant increase in healer DPS, certainly not enough to cover the huge gap between WAR and PLD DPS.
Aside from allllll that, WAR also posesses raid utility with Path, Eye, great tank DPS, and the ability to mitigate all types of damage and not being locked into being a magic or physical specialist.