This is true. But this doesn't really matter outside of raiding when you are desperately trying to hit skips or battle milestones. In PUG relevant content like zuvran, you don't know the quality of the healers and they don't know you, just stay in tank stance. Unless its truly trash/mindless content, the 1.5 second faster kill time from playing loose with tank stance for max dps is never worth a potential wipe.
This.
However, a proper OT Warrior will know when to and not to use the Butcher's Block combo, and watch their own aggro meter. The potency loss in a warrior alternating Storm's Path and Storm's Eye (which also adds in a damage debuff on the enemy) is completely negated by a paladin's gain in not having to swap to tank stance or having to use Rage of Halone. And the gain is quite significant, sometimes enough to push a phase or not.
Of course, good luck getting that without a steady raid group.