The best special ability ?

Hello everyone , it's my first post here and sorry if it's not the right place :)

I just started this moring training 3 of my players for a special ability:

Attachment 35572 Attachment 35573 Attachment 35574


And now i want to train more players (1 or 2 more) , but i don't know which ability is the best for me , that's my team:

Attachment 35576


THANK's FOR YOUR HELP :D

Training defenders FK special ability is waste... Playmaker SA is uselless... Players should train SA while they are 4* or at least 5*... Aeral ability is good SA for DCs... Corner SA might be useful for a winger or MC... Shadow striker is good for AMs...