Why is the Toothbreaker Grips better as an offpiece than Turret Mechanic's Legwraps??4 Piece is using Toothbreaker Grips as the offpiece.
2 Piece is using Toothbreaker Grips, Turret Mechanic's Legwraps and Earthripple Shoulderpads as the offpieces.
0 Piece is using Toothbreaker Grips, Turret Mechanic's Legwraps, Earthripple Shoulderpads, Eye-Catching Gilded Robe and Slagbomber's Hood as the offpieces (in this case in replace of all the tier pieces).
When you take Turret Legs + T17 Gloves (using 680 heroic values) you gain:
+23 Mastery
+318 Crit
-177 Multi
-164 Haste
over Toothbreaker gloves + T17 legs.
Wouldnt you want to max mastery if that's the top priority for secondaries?
Wouldnt Crit > Multi too since Crit also generates Imps from Doom, high proc rate = more reliable fury generation and max Imps spawned faster?