To me, it seems SE's plan for WAR has always been a self-healing tank, it makes sense, PLD mitigates damage, WAR heals it back. two very different styles and a nice diversity in the tanking classes.

the problem is the scaling. bloodbath returns 25% damage as a heal, storm's path gives 50%, while mercy stroke (should you ever manage to pull off the timing in an instance, esp 8man ones) and inner beast return 300% and this just isnt enough healing at endgame.

there's two ways to resolve this, WAR needs to put out more damage so those self heals effectively return more HP per hit, or increase the percentages returned. As tanking equips generally focus on VIT and can be used by both PLD and WAR it would prove hard to increase WAR's damage output without altering its base damage, meaning it'd become more competition for DD classes, and i feel that area is pretty well balanced, altering that has a serious chance of causing imbalance. The other is to increase the amount of health returned from damage done.

giving WAR a trait at level 50 that makes bloodbath and storm's path return 100% of damage done as healing would work well, add in a 200% return for critical hits and that really should do the job. the mechanics could also alter bloodbath slightly for AoE hits, with a 100% return on damage to targeted mob, 25% for all others, to prevent it from becoming overpowered (no pun intended). making it a level 50 trait also prevents WAR from being too overpowered at earlier levels, as its only during endgame content that the majority of the difference between %mitigation and static healing returns becomes an issue.