Dzeko, Lukaku, Cisse, Rooney, Benteke...probably even Defoe, Hernandez Lambert, Giroud, Podolski all are at least at the same level. Anyway, I think you are massively overrating Ba. He had two good first halfs of the season with Newcastle, but he can't score regularly when he is not playing every week. A good striker should also do that as a back up.