So I just got Gameiro and I play him on the RW because I have Griezmann and Belotti IF up front, his shooting is decent, he's a good finisher, he has quite the shot power too. His finesse is decent too, a problem I did notice was his ball control so I recommend you apply the Marksman chem style. He's very similar to the 86 Martinez card but he's slightly worse. 86 Ben Yedder is probably better than him too. I'd rate him 8/10.
Shot Power
High Attacking Positioning
Jumping
Good Poacher due to high reactions
Ball Control
Lacks Strength