Gnomeo

I was looking through my general skills on my Mistweaver Monk, Gnomeo, and saw [Dual Wield]. After that I saw another play dual wield two maces on the Mistweaver specialization. When I tried to dual wield two maces it would not let me equip a one-handed mace on my offhand. I prefer the critical chance from each mace over spirit from my staff. What can I do to fix this or is it just not possible?