Honestly the issue isn’t exactly dungeon design, it’s spec design and the hamstrung mechanics fury is constrained by when it comes to it’s ability to deal with multiple targets.
To premise the problem lies solely with the meat cleaver mechanic and it’s lack of balance with fury’s toolkit.
Previous seasons where fury did well enough it had the capability of doing uncapped damage to enemies nearby it through abilities like Bladestorm or Odyn’s Fury which had some oomph behind them, frequent procs such as Wrecking Ball which gave a sizable amount of passive AoE potential that wasn’t constrained to just 5 targets.
This has now somewhat been split between the two hero talents where Slayer is more Cooldown focused and Thane provides more static with thunderclap/blast. However neither really shines as well as previous iterations of fury which had access to both types of damage profiles of solid burst and solid sustain.
Meat cleaver’s balance is also heavily hamstrung by fury’s ST capability. Realistically it’s a mechanic that’s long overdue for removal and Fury does need a sizable rework in the way it handles AoE so it’s not left in the dust almost every season. Yes some of that could be done in the class tree to provide utility options for all warrior specs, but the baseline of fury has so many missteps that they would need a decent help to bring them up to par with what is expected group performance wise in keys.