I don't understand what part of it you're not getting? All tanker attacks do 20% more damage at base now. That's the same amount Bruising adds. If you use the exact same attack chain damage should be identical. In fact, it should be higher, since the first hit will also be 20% stronger, where before the first attack to apply Bruising didn't benefit from it. And if you use a better attack chain that doesn't use the T1 attack with its probably worst DPA, higher DPS still.