Yeah scaling problem.
If a sac wants to trade HP for dmg like normal you might give up 8000 HP (60 or 70%) to get maybe an extra 450 dmg vs 60% to 70% final res = 180 to 135 more dmg against players and mobs with 1000s of HP.
That's one of sacs main mechanics and it really sucks atm. I just roll with high res and high HP now and rarely use punish properly anymore. Punish without meeting the enemy hp% req really isn't that special + ends up costing 5ap/1mp/1wp and self dmg. And it can't be used until you reach 25 angrrr. And you have to be in CC.
Sac can still be very useful but all the fun stuff is broken and getting more broken as other stats, classes and mobs progress.