Why should Ac Milan employ Allegri? I don't think AC Milan needs to bring back their former manager. Allegri managed for almost four years, winning the Seria A championship between 2010 and 2014. Milan wants a new manager with new strategies, they do not need to hire a manager who failed to improve this season, Juventus has the best players to win their games this season, but they struggled to win their games. Milan will compete in the next Champions League and the manager must prepare the players to play at a high level. Allegri has failed to improve Juventus, who only competed in the Seria A this season. So Allegri is not the perfect choice for Milan.
The best players? I don't think so at all my friend.

There are significant weaknesses in the squad. Especially in the midfield area I mean. There is a big lack of score contribution of this team. We have seen this during the whole season. Only 54 goals in 38 games? This is bad statistics if you want to become the champions.
And I don't believe Allegri is the person at fault here. Juventus didn't have very good finances as far as I know and didn't make necessary signings last summer. Here we are now. Otherwise Allegri had an amazing history with Juventus full of Serie A titles.