Good to see someone took initiative and made a detailed outlook on things.
I kind of noticed that too when I was examining how well it would all play out in an actual combat scenario trying to keep IB up 100% of the time. At the start you can get a good 30 seconds of IB effect for about the first minute and a half and of course Vengeance for another 30 seconds. However, afterwards you start to get gaps due too Vengeance/Berserk's cooldowns, and then there's the unavoidable overlap with IB and Vengeance reducing the amount of uptime that your mitigation abilities can truly be up at any given point.
Anyways back to the shield thing, I see alot of folks overlook the Blind Effect on PLD's Flash. Overall it seems to be a solid % in accuracy reduction so you actually can evade things with some reliability, but like blocking it's all chance so it's impossible to predict it's mitigation prowess unless the mob is immune to it's effect.
Either way I see alot of potential for both PLD and WAR having a very symbiotic relationship in things like coil and primals.
PLD's support WAR's by pumping out Blind (Flash), Stoneskin, STR down (RoH), Cover.
WAR's support PLD's by Damage down (SP), Slash Dmg up (SE), Holmganging opponents away from PLD (IE moving them out or range/binding so no damage outside of ranged attacks).
And really nobody could tell me having STR down and Damage down 100% of the time together wouldn't be glorious for everyone? (Hell throw in Rain of Deaths effect and the occasional Virus too, all the possibilities are makin me jittery.)
Ahh, but I digress rather than looking at the black and white of which would be better, peeps should be looking at what they can do together.
Examining both jobs they're pretty much on par as both take CC abilities from one another and none of the respective changes actually affect the CC abilities.
Now that Wraith stacks are more usable WAR will have a bit more flexibility damage wise, however this will have a double edged effect. Mainly you can use Unchained and not have that mitigation or use IB and not have that extra damage output forcing you to be a bit more decisive.
Just being reduced from 300% to 100%.