Make act 5 mercs dual wield

[Moonpaw]

I tried allowing act 5 mercs to dual wield, after replacing their appearance with the barbarian player look. I gave it the "Left Hand Swing" skill the barbarian hero has but that alone didnt do the trick
I can give him a second weapon but funny enough it just disappears into the void

What do i need to do? is it impossible?

[ascar]

hello

i tried too and didnt manage, i just recreate axe barbarian (one handed axe only) and keep the sword barbarian (one or 2 handed sword only)