I have to admit after a couple of weeks of playing I find the weird formations that are successful to be a little bit stupid. One guy in my league plays

----- ST ST ST -----
-------- AMC ---------
--MC - MC - MC--
---------------------------
DL ----- DC ----- DR

He wins almost every game 4-0 or 5-0 with only one centre back. In fact the only game he lost was against me. He has the 2nd highest rated team in the league and as mine is the highest, I think his highly attacking style meant when playing a team with a higher quality, he couldn't keep goals out. I've just tried his style against another team (3 strikers with 1 DC, DL and DR) and I won 4-0...

In a real game you'd get hammered with 1 CB and the 3 strikers would probably trip over each other trying to score.