Gomez is a very good finisher but plz don't forget that he missed some important scoring opportunities against Real and Chelsea last year (semi-finals and finals, respectively). So, it's not like he is a sure thing if it is about capitalize on opportunities in important games.
You are complaining about Dzeko's working outside of the box? You should be glad to have such a striker. Gomez can disappear for the whole game without any usage for the team...you cannot afford that against top competitors. Just spend a look at the half-finals against Italy in the EC 2012.
Iirc, Dzeko always was a working striker (seen him at Wolfsburg). You will need such a type if you want to have a good working closing-down.
Don't forget that scoring in a team with Robben, Müller and Ribery isn't very difficult. Anyone can do this.