I tried for a small while with Pescara in Serie A. Predicted 20th.
Key was to set manual marking with the wide strikers... It will give you a 451 formation when defending. I asked my wide strikers to mark the fullbacks when teams were using wide play. However, in Italy I came across formations where the midfield is loaded so I asked the wide strikers to mark the wide CM players (if any) to match their number in the midfield. That is the charm of football management, not just using some plug and play tactic, but also adapting to the opposition tactics.
As far as the results go, my ****** strikers were always able to score, but my ****** defenders were not always able to defend. So I guess, it comes down to the quality of the players as well as how much damage the opposition decides to inflict on you, based on Home/Away games, your odds, your pre-match conference comments etc.