During my 2 years here ve seen lot of people coming here with good teams and surprising results against, if I count all the times that this situaion happened and all times Ive said "ohh, look, again 3 defenders" probably is arround 30 times in 2 years LOL
I belive in that 1st, are the players, thats the 1st under all.
Then if I have to do a ranking of formations, the formations with 3 defenders are less stable and usually have more % of surprising result against despite better Q. because if a the players fail, formation chrashes.
That's of course my personal viewpoint and my personal feeling about that, thats why I use always 4 defenders in a 4-3-3, 4-3-1-2 or 4-1-2-1-2 (diamond).
Everyone have to play with what he feels that is the beteter because nobody knows how the game works really LOL