My Assassin has life and mana leech equips that exceed what the life steal and mana steal in the advanced stats. Is there an unreported bug about that?
The values on your weapons aren’t applied to the advanced stats (life leech from a weapon only applies to that specific weapon).
Life/Mana Leech on Armor/Skills will stack with Life/Mana Leech on Weapons. For dual-wield Assassin and Barbs, the Life/Mana Leech on Weapons is independent from each other. Meaning if both Weapons have Life/Mana Leech, they do not stack with the other Weapon.
Ex: Weapon 1: 5% Life Leech; Weapon 2: 8% Life Leech; Armor: 3% Life Leech
Weapon 1 will have a total of 8% Life Leech when it lands a strike while Weapon 2 will have 11% Life Leech. Any skills, such as Cobra Strike, supplement both weapons. Also note that the effectiveness of Leeching is reduced on Nightmare/Hell Difficulty and by Monster “Drain Effectiveness”.