It's not that Butcher's Block is strange because it doesn't have a secondary benefit beyond marginally increased damage; it's that only PLD really has a "primary" combo where the t3 bonus for that attack is anything except for increased damage (though it should be mentioned that RoH actually gets both substantially increased damage as well as a secondary benefit). Snap Punch is just 180 compared to the 130-150 that you get out of the Opo-opo and Raptor form attacks. Greased Lightning isn't unique to it, so that benefit has more in common with Wrath generation than the secondary effect of RoH. Full Thrust for DRG is the same way: straight up big damage with no secondary benefit.
Really, there's much stronger evidence that Rage of Halone is the outlier, as opposed to Butcher's Block. Though it's important to keep in mind what I said at the start of the thread: in order to mix up the PLD rotation with an "inferior" enmity attack that applies a debuff, you've gotta buff RoH's damage by a *crapload* to preserve the enmity/damage balance (and doing so would actually push up PLD damage by ~31 potency per GCD).
The only durability balance that it would really address it accounting for the Shield v. No Shield discrepancy. 10% STR isn't *nearly* large enough to make up for the straight up inferiority of Wrath and the WAR CD suite so you'd still have a *long* way to go even if you did swap it around.As a side note, if Butcher's Block reduced STR by 10% and Rage of Halone did nothing, the 2 jobs would be much closer to being balanced in terms of durability.