1st page post updated:
-ADDED KEY PLAYERS for every single formation.
The key players are those who made most impact in the team while using that kind of formation in my personal experiance.
For examplle, the 4-5-1 V style needs a good DMC possible with Playmaker ability cause most of the counter attacks start there.. he's the core of the team. Also AML/AMR with Shadow strikers manage to score alot of goals from distance as we know.

In the defensive 3-2-3-2 GK - DC DC DC - DML DMR - MC MC MC - ST ST: Defensive wall and Aerial Defenders did great job as we use this formation to counter any team that has attacking down both flang team and and any DC with defensive wall would block the long distance shots better, any DC with Aerial Defender ability would stop most of the crosses and so on..
If you got any questions don't hesitate to ask.

p.s: Every player is important but there are some that count more i would sugest to always build equal and balanced team and not just concentrating on attacking group.. as 90% of my friends do.