If your tactic is successful, why would you want to change it?
But my suggestion is it seems like you're playing two different styles. You've got some roles and TIs for a counter attacking style (pass into space, distribute quickly, TM on attack, wing backs on attack) and some other roles and TIs for possession play (play out of defense, overlaps, counter-press, distribute to center backs, two playmakers close to one another). So if I were to change this tactic I would either play it a full counter attacking style or a fully possession depending on your players and how you expect the opposition to set up.
I personally love the target man so as long as Mariano has the attributes for it (strength, balance, off the ball, jumping reach, work rate), you can still use him there. Target men need space and support to be successful. You're playing with a high LOE and he is on attack. Most likely what is happening is he is surrounded by players when he is being passed the ball so he either loses it quickly or doesn't even receive it. So think about how you can get your TM more support and more space.