I have a theory why he is beast with Fiorentina and not with us besides of the pressure of the big club
My theory is the Role Model
In Fiorentina, everyone want to accept or not the first role model that come to their mind when they develop Vlahovic is the one and only Gabriel Batistuta. They nurture him to play like that kind of predatory striker, power shoot, try to finish every chance from every angle, and more or less he try to emulate that in his style of play
When he join us, his role model start to change over time to the one living super player in front of him. which is Cristiano Ronaldo
He started to try to run with the ball, curl the ball , he train that curler freekick ,he trying to be super precise in his shooting
But he is not that type of players, he loses on 1 vs 1, those precise shoot becoming a super highly precision to the crossbar and the woodwork
All of the thing that happen made him feel inferior and not playing up to the standard, this starting fuck his mind. This explain why in the start of his career with us he still have some of his old predatory instinct. But that eventually lost over time when he try to emulate Ronaldo style of play
If he choose someone like Trezeguet or even Higuain, he will learn more technique to elegantly put the ball in the back of the net (develop his killer instinct for the goal) . Or someone instruct him to follow the style of play of Trezeguat, he will be more complete then the Fio's Vlahovic