You only have to look at Real Madrid to see what happens when you think only of attacking. The thought process of their president Florentino Perez (who makes new signing decisions, not the manager) must look like this:

1. Get a €300million loan from a bank.

2. Go out and buy as many attacking, 'flair-players' as possible. (Ronaldo, Kaka, Benzema).

3. Sell lots and lots of Real Madrid shirts.

Notice that winning trophies does not enter the equation. Indeed, Real Madrid got dumped out of the Champions League by a fairly ordinary Lyon side.