You are right AC Milan has spent much of money to improve their team and with Massimiliano Allegri as new coach we should have to be patient. Allegri teams are known for starting slowly and getting better as season goes on so it will take few weeks for players to fully understand his style. His past success gives hope for good season nothing is guaranteed in football and only time will tell if his methods will lead to success this time or not.
Massimiliano Allegri is a wonderful coach and the reason for his slow start is because he focus more on building a strong midfield to give the team a domineering with his favorite 3-5-2 formation before anything. This may seem to delay their attacking and also makes the defense vulnerable but the reality is that he prefer massive defense and massive attacking. If he is giving the necessary supports he needs, I'm sure he will be able to rebuild AC Milan and restore their lost glories.