I think that if you're going to do this, play to his best and attributes.
If he is fast and technically-gifted, get him to move into the channels and get past his man with skill, then cross to the far post. If he is not really fast, but creative and tactical, then get him to cut onto the inside and cross near post. Tends to work well because he'll know where to place the ball. Work on his Crossing if it's poor.
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The thing with the X-Mas tree formation is that the AMC's act like second and third strikers. They should move into the channels and support the striker whenever and wherever. The three midfielders should have a Deep-Lying Playmaker and two central midfielders that play either narrowly and are like destroyers with the playmaker, or play wide and have the fullbacks in overlap.
With the 4-2-3-1, you can actually have a narrow one (with there not being wingers) and have them as AMC's, and edit their Player Instructions to a winger so that they act like them with similarities. Vary it and have one cut inside and the other move into the channels. Have the mentally-strong AMC cut inside and the faster move into the channels.
Apologies for such a long response.