I would imagine it would depend more on how often Warrior needs to use Inner Beast.
- If you need to use it for every tank buster, then you have to save it since those are generally ~30s each.
- If you don't need it for every tank buster, but you still need it, then you've got that damage reduction up ~18s/63s.
- If you don't need it at all, then you use it for Fell Cleave and this discussion is moot.
Paladin would need a really incredible block rate if scenario #2 was in play to beat out Warrior.
Edit: If I actually had to mitigate stuff and MT on progression, scenario #2 was usually how I played it. Scenario #3 is a more HW approach, and seems to be the way to go for Savage.
Edit2: In HW, Warrior also gets 10% extra Parry rate if they are holding IB for tank busters as well.
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