St not scoring depends on lot of things.

1st we need more infos , waht kind ( and level, difficulty ) of competition your are playing ( high % or low % ? ) cause in my eyes to be honest ( maybe cause i got used to player with 200+ stats ) is a very very weak ST and would hardly score against defences with 2 dc ( or 1dc but a good one ).

2nd how you are playing ? do you put him in condition to give his best ? cause sometimes is the manager way of playing not compatible with player the problem and not the player

About this thing '' wingers scores more than St s '' , usually is because wingers are always involved in 1v1 duels , what ever formation you you meet , they will be always 1v1 ( winger vs full back situation ) and of course if the winger is very good and not playing always against good fullback will score very often. STs instead can be against 2DC mostly ( or even 3 ) , that means always double marking so unless is a Great player , 2 average DCs can easily stop him togheter. So if you want to play 1ST formation he needs to be a great one , so strong that even 2 DCs can't stop him.

I personally don't use STs ( for years ) but i played with them in the past and i used sistems with 2st or a st + support ( amc ) to match oppo defence numbers , i advice you to do the same , if they are not great give them support with amc or a partner .