Defensive mentality doesn't mean lame or loosing mentality. Actually, most teams in champions league use these kind of tactics when facing too strong opponents. Of course you can win leauge and CL with each tactic. You can play offensive football with 4-5-1 but the way the formation puts players on the field, it's more strong with defensive mindset. There are much more attacking formations/tactics out there. Again, that's not a disadvantage.
Wingers belong to the midfield. That doesn't change my proposal.I said midfield is the key point. All players are key players, especially at top level. Midfield still remains the key part of the field and midfielders (that is, defensive midfielder, central midfielders and wingers) are expected to carry on the game.