Milan is just a bad team in the first place, they have Gimenez, Felix and Walker, their performance aren't that bad actually, they can still perform. Bologna's squad is a combination of young players who not able to reach senior team, second tier players and old players who no longer playing in senior team, yet Milan still lose.
Better to sack the manager instead, maybe Italian teams good when they get managed by Italian managers too. Inter, Atalanta, Napoli, and Juventus are managed by Italian managers. Milan was better when Stefano Pioli was the manager.
AC Milan With its current coach, Sergio Conceição, it is not as good as you have said that the appearance at the beginning of the season was not so good and like a wind in the game, it was also not good in giving tactics, even though it has players like Gimenez, Felix, and Walker, if it is not handled properly, then the results we can see for ourselves AC Milan, they are still stuck in 8th position in the standings and their last two defeats were really disappointing, of course there must be a revision in the squad and management that is so lacking in paying attention to the shortcomings in AC Milan's playing style this season.
Conceição seems to have failed to implement a strategy that fits the current players in the AC Milan squad, and I think the management's decision to bring in Conceição in the middle of this season was a failed move.
There is no longer any possibility for AC Milan to compete in the top 4 now because their performance has been quite bad in the last few matches, losing to lower-ranking teams or in terms of quality below them, so I think there is nothing more to expect from AC Milan at this time.
Even though AC Milan had a 1 goal lead in the first half, in the second half their performance declined so that Bologna managed to take advantage of the carelessness of AC Milan players to turn things around, this was really a bad match for AC Milan.
Though I saw this particular encounter against bologna as a tough and fierce encounter but I never expected Ac Milan to lose the game because when watching the first half of the game they were doing pretty fine, and I was even thinking if they can kill off the game by adding a second goal, but I was actually wrong, they are not just good enough to beat this bologna side, in the second half bologna seize every opportunity that came their way and eventually won the game, which will now make it very difficult for Ac Milan to qualify for a place in the uefa champions league, because it's now 8points that separate them and Juventus that is occupying that fourth position.
Then as for the new manager, I really don't think he is a bad coach though, what I sense is that the players at Ac Milan hasn't yet buy into his coaching idea, this is a move that would have been better if it was done during the summer were preseason would have been very instrumental and beneficial to him as his player, but right now, they are still struggling to buy into his playing system, let's see how things goes between now and the end of the season, because am positive that if things goes bad the more, he might lose his job because result is very important and instrumental for a manager to retain his job.