Sunder - Dual Wield Damage

Sunder seems to deal far less damage than expected when dual wielding.

With only weapon 1 equipped my average hit is 2094
With only weapon 2 equipped my average hhit is 1253
Resulting DW damage should be 2343 but instead it's 1250

Furthermore im not even sure if additional critical multiplier is being calculated correctly.

If the skill is only meant to be used single handed then the tooltip is missleading

Thanks

+1, I was watching my sunder hitting bosses. 2h + shield hit for 550k hit.

2h+2h hitting for only 587k hit ?

I have gas grenade fully break enemy armour before hitting both hits.

My weapon damage is similar , not too far from each other :
weap 1


weap 2


I suspected that Main hand hit Consume the Fully Broken Armour, so no Crit guaranteed for Off hand hit. I might be wrong, but please looks into this matter.