A couple of seasons ago I had every striker injured so I had to use the free youth player who was about 15Q lower (3 Star) than the average player in my squad. Yet he'd get hattricks every game got 9's and 8's when I had an 8 star striker next to him performing 7's and the odd 8.
I guess some players just have a hidden goal scoring talent in this game and its a gamble to find them.