for unlocking stubborn defenses ,you need someone who can weave his magic in the final third,someone with exquisite close control and dribbling
as well as someone who can make that visionary through pass(well we have vucinic who can do that) and Suarez's movement is brilliant..suarez can do all the above as well as putting the ball in the back of the net.
In all these characteristics i mentioned above Dzeko is mediocre in those aspects,he's just a pure static poacher...