To rrra
Would you consider using Titan's Grip now instead of Divinity for both the might aura and physical pierce and perhaps switch your Mercenary's armor to Steel Carapace?
Also have you tried this build with the Deadly Sin Sword (and then use an Act 3 mercenary with Azurewrath, Dragon's Bulwark, Templar's Might or Steel Carapace, and Focus)?