I actually had this exact problem long before the rework, probably in Shadowbringers. I failed floor 150 because of lack of damage, although I had tried to use one of the special disguises which might have been a wrong decision.
But it is a tank. It's not damage dealer and tanks have a trait that reduces damage that used to be optional by turning on or off their stance.
But since you want to compare tank damage, let's compare it to GNB at level 60 over 60 seconds, assuming they already prepped as much fire power as they can for their burst windows.
Gunbreaker
Code:
00:00 No Mercy (20%)
00:00 Sonic Break 300 + 600 over time
01:00 Danger Zone 250
02:50 Gnashing Fang 380.
05:00 Savage Claw 460.
07:50 Wicked Talon 540.
10:00 Burst Strike 380.
12:50 Solid Barrel 320.
15:00 Burst Strike 380.
17:50 Keen Edge 150.
20:00 Brutal Shell 240.
(No Mercy ends. 4000 into 4800 potency.)
22:50 Solid Barrel 320.
25:00 Keen Edge 150.
27:50 Brutal Shell 240.
30:00 Solid Barrel 320.
31:00 Danger Zone 250.
32:50 Gnashing Fang 380.
35:00 Savage Claw 460.
37:50 Wicked Talon 540.
40:00 Keen Edge 150.
42:50 Brutal Shell 240.
45:00 Solid Barrel 320.
47:50 Keen Edge 150.
50:00 Brutal Shell 240.
52:50 Burst Strike 380.
55:00 Solid Barrel 320.
57:50 Keen Edge 150.
60:00 Brutal Shell 240.
Paladin
Code:
00:00 Fight or Flight (25%)
00:00 Goring Blade 700
00:75 Spirits Within 270
01:50 Circle of Scorn 100 + 150 over time
02:50 Royal Authority 380.
05:00 Fast Blade 200.
07:50 Riot Blade 280.
10:00 Royal Authority 380.
12:50 Fast Blade 200.
15:00 Riot Blade 280.
17:50 Royal Authority 380.
20:00 Fast Blade 200.
(Fight or Flight ends. 3520 into 4400 potency.)
22:50 Riot Blade 280.
25:00 Royal Authority 380.
27:50 Fast Blade 200.
30:00 Riot Blade 280.
30:75 Spirits Within 270.
31:50 Circle of Scorn 100 + 150 over time.
32:50 Royal Authority 380.
35:00 Fast Blade 200.
37:50 Riot Blade 280.
40:00 Royal Authority 380.
42:50 Fast Blade 200.
45:00 Riot Blade 280.
47:50 Royal Authority 380.
50:00 Fast Blade 200.
52:50 Riot Blade 280.
55:00 Royal Authority 380.
57:50 Fast Blade 200.
60:00 Riot Blade 280.
That's
9500 on PLD over 60 seconds and
9650 on GNB over 60 seconds.
To be honest, I included something inside of their buffs that wouldn't have fit without skill speed as well, so it wasn't a perfect calculation. But with only a 150 potency difference, there isn't much difference between the two tanks over 60 seconds at level 60.