Very simple. To fix the current FF14 WAR, SE should take a page from Blizzard. Make the WAR job more similar to a Brew master monk.

Defiance will:
reduce damage by 5% per wrath stack, max 25%
Increase HP by 25%
Increase parry rate by 10% per wrath stack, Max 50%
SE combo will allow stagger damage. 80% damage received, with 20% staggered over 10 secs
Last but not least, SP combo creates a damage absorb shield for 10% of max HP, with 15 sec CD

Done. WAR is fixed.