For me shadow striker is also the best. The player with this SA always is on average the best performer in my team. After that I'd say freekick taker and 3rd corner. If you have a player with freekick and shadow striker it's really the best SA combination in my opinion.

Right now my 2 wingers are 1 freekick + playmaker and 1 shadow + corner and they are both very good performers and share most man of the match rewards between them.