Yeah, I tend to believe in natural attributes and style. Like
@robp135 mentioned, players tend to be who they are from quite a young age. They refine those abilities rather than genuinely adding brand-new ones. If you go back and watch Bale at 17 for Southampton, you see the exact same player he later became, just stronger, more mature, and freed from defensive duties.
It's not that I think Savinho can't ever improve his shooting, it's just that it isn't his natural inclination. On Saturday, when he had the beating of Mykolenko, his next instinct was never to drive toward goal and shoot; he was always looking for the layoff, the cross, or the pass into someone. He just doesn't have that goal hunger. Someone like Johnson was the opposite, you couldn't train him to do much in general play, but he had the natural instinct to get on the end of chances and score. That's why he consistently found himself in those positions.
I'm not claiming to be an expert on what ultimate system suits Savinho best, but basing it on what I've seen, a player who prefers creating for others and linking up with fellow attackers is naturally suited to playing on their stronger side. When you play on the inverted flank, your instincts really need to lean toward being a direct goal threat. Having watched Savinho at his best, that was clearly on the left where the pitch opens up for him. Even at Emirates Marketing Project, half of his goals came from the left despite playing there only 20% of the time. I get the manager's logic, if you could unlock a reliable goal threat to go with his dribbling, he'd be world class, but I just think he's far more of a traditional creating winger than an inside forward.