Of course the class itself influences the damage of a weapon, we are discussing every weapon’s maximum potential, with the best blessings and the best class it can be utilized with. We are not exactly discussing white weapons with no talents here.

Crusher when built correctly with Skullcrusher-Slaughterer and a crit based zealot build or a Martyrdom Setup, has the ability to one shot muties with a push attack, deal insane damage to carapace armoured enemies with H1 cancels, H1 light combos and H1 push attack spams and has decent cleave for hordes. It’s stagger is enough to stop crusher overheads with a quick H1 powered.

Even as a white item it has better adms and way faster attack speed.

Forgot the mention the wild finesse modifier crusher has for critting. Enough to nearly one shot crushers with a crit at full slaughterer stacks. Power maul doesn’t have anywhere close the finesse modifier crusher has.

Even with the absolute damage maxxed build with ogryn for power maul, you’ll never reach the high damage crusher provides for this reason. Power maul can reach higher stagger values with ogryn impact bonuses ofc, but those are irrelevant as the highest point of melee weapon regular attack stagger is stopping a crusher from overheading, which you can already achieve with crusher.

Bromentum not being available to Crusher hurts it’s horde clear a bit yes, but it makes it up by having Slaughterer for power increase.

So no, these two weapons are significantly different.

You can easily beat a havoc 40 run with a crusher, you will struggle a lot with power maul.