I don't need any facts, this forum is all about opinions.
If you want to go off stats, Modric was a shit player at Spurs because he rarely scored and got any assists and Henderson was much better than him at Sunderland because his stats for assists and goals were far better. Stats aren't the bee all and end all, watching a player 90 minutes in a match helps a lot more.
Same can be said for Ozil, i used to have many debates with my friends about this man, my opinion was that whenever i watched Madrid (which was regularly when he was there), he seemed to go missing a lot in games and fluttered in and out, some of my friends just paid attention to his assists and because of this, he used to say how Ozil was the best in the world in his position and was much better than Iniesta. I think anyone with half a brain can see Iniesta is far superior regardless of how superior Ozil's stats were at Madrid.
I have seen Jackson Martinez plenty of times and he looks a more intimidating striker than Dzeko, looks the type of striker defenders hate playing against. Dzeko is a bit of a fairy and is too easy for defenders to play against IMO.
If you do want to go off stats however, Jackson Martinez played 41 games this season, scoring 32 goals in all competitions. He scored 7 goals in 8 games in the CL as well and one of those appearances was coming off the bench.