Actually I tested with a few players that were either AM or ST, and sometimes AM+ST doesn't increase, sometimes it does. I don't get it anymore.

I tested by editing their position ability, from 1 to 20 and back.

I tested now, and these combinations also do not increase CA:
CD + DM
DM + CM
CM + AM

This increased it:
AM + ST

tweak = improve (a mechanism or system) by making fine adjustments to it

but this performed worse, right?

Thank you for the amazing answers Delicious. How about player traits? Do you recommending developing certain player traits for certain positions on this tactic (of course, if the players have the attributes for it)?

How do you use attitude (balanced, positive, etc.) depending on the opposition and Away/Home?

How about other factors?

I've noticed that when you're not a favorite in away matches, you actually have more success with Attacking, even though Cautious or Balanced might seem like the normal choices. This is subjective, I haven't done any proper tests except scum loading.

I still don't get it. So you always start the matches with Balanced attitude, then switch during the match? I would guess that an away match against hard opposition you could start with Cautious or Attacking for better results. I've actually had better results with Attacking in these situations.

"Away to the best sides you play." ... cautious? balanced?

and playing at home, can I have it as attacking all the time?

How do you change mentality depending on the opponent? And is there anything else that you change?