Don't know about optimal, but i use default WD combat settings in trinity, with this build/items setup:
[Trinity] ------ Equipped Legendaries: Items=12, Sets=1 ------
[Trinity] Item: Ring: Ring of Royal Grandeur (298094) is Equipped
[Trinity] Item: VoodooMask: Tiklandian Visage (221382) is Equipped
[Trinity] Item: Bracer: Strongarm Bracers (193692) is Equipped
[Trinity] Item: Belt: String of Ears (193669) is Equipped
[Trinity] Item: Amulet: Rondal's Locket (197818) is Equipped
[Trinity] Item: Ring: Stone of Jordan (212582) is Equipped
[Trinity] Item: Mace: The Furnace (271666) is Equipped
[Trinity] ------ Set: Raiment of the Jade Harvester : 5/6 Equipped. ActiveBonuses=3/3 ------
[Trinity] Item: Legs: Jade Harvester's Courage (338041) is Equipped
[Trinity] Item: Shoulder: Jade Harvester's Joy (338042) is Equipped
[Trinity] Item: Gloves: Jade Harvester's Mercy (338039) is Equipped
[Trinity] Item: Chest: Jade Harvester's Peace (338038) is Equipped
[Trinity] Item: Boots: Jade Harvester's Swiftness (338037) is Equipped
[Trinity] ------ Active Skills / Runes ------
[Trinity] Skill: Summon Zombie Dogs Rune=Leeching Beasts Type=Spender
[Trinity] Skill: Horrify Rune=Face of Death Type=Spender
[Trinity] Skill: Soul Harvest Rune=Siphon Type=Spender
[Trinity] Skill: Haunt Rune=Resentful Spirits Type=Spender
[Trinity] Skill: Locust Swarm Rune=Devouring Swarm Type=Spender
[Trinity] Skill: Piranhas Rune=Piranhado Type=Spender
[Trinity] ------ Passives ------
[Trinity] Passive: Jungle Fortitude
[Trinity] Passive: Spirit Vessel
[Trinity] Passive: Grave Injustice
[Trinity] Passive: Creeping Death