Icardi scored more consistently then Morata did and was top scorer.
I don't know FIFA stats well but my first reaction wasn't Morata but that first, Chiellini doesn't deserve that.. Secondly Dybala only has 78, kid is supremely skilled and if he has under 80 I'm guessing he won't have good enough dribbling, passing for agility stats.
Morata had 13 goals in 2065 minutes (Serie A and CL). A goal every 158 mins.
Icardi had 23 goals 3570 minutes (Serie A and EL). So a goal every 156 minutes (im not including Inter's matches against that icelandic team in EL qualifying)
And the Icardi took penalties, and Inter played some pretty average teams in the EL. Morata is superior when it comes to assists, key passes, chances created, and fouls received.
Dybala's dribbling and passing stats are pretty good. His defensive and strength stats on the other hand are terrible.