Mandzukic at his best age averaged 12-15 league goals/season with 28-30 league appearance.
15 league goals per seasons is average for a striker, great for a SS, mediocre for a finisher,
good finishers average15-18 league goals per season and trully gifted or on form ones average +20 league/season.
Manzdukic is an established striker, but was never a top finisher, considering his age, he is now past it and is unlikely to become now.
Paired with a SS that score 12-15league goals, like Tevez, together they would complement each other and score the necessary ammount we need to compete as champions.
Dybala though is not that good at finishing, he is great at other things, but he needs a really deadly finisher besides him, thats why we should have opted for a more specialized finisher, even if his overall skills are lesser to Manzdu's.
But prolific finishers are hard to find, they are rare and expensive, Marotta never managed to get one in his career and never will.
Thats why his best bet is to buy one in development, Marotta was one, but he got him with a buy back clause, by the time he reaches that potential.
Immobile was too, but he just sold him off. Berardi was his last chance, but he preferred Zaza, who averages like 12.5 league goals/season...