Yes, although I have far more faith in Ibra's mental strength than Bonucci/Higuain, but being Ibra dependent is it's own can of worms.
I see where you're coming from. However a team always has it's own hierarchy with leader type of players and squad type of players. One of the many problems we've had in recent years is that few to no players in our squad have the mental strength to become leader type of players. Loosing is part of the sport. Part of this game. But the way we lost to Atalanta (not only, Inter comes to my mind as well) shows how little personality this squad currently has.
I once thought Romagnoli could be one of this leader type of players in current Milan. Not sure after the past 6 months of this season. Jack seems to be one if you believe the rumours, but technically he's not a player I don't want to dependend on.
Bonucci and Higuain have been thought to be those leader type of players to guide a younger generation. They weren't. End of story.
Being Ibra dependent in my eyes is as long a problem as we don't bring more of those leader type of players to guide the squad type of players. It's like taking the Maldini of the 2000-decade and put him into this team (bar Ibra). He'd be tremendous, but you can't expect winning Serie A or let alone CL if you don't add Rino, Nesta, Ambro etc.; football is a teamsport, and being dependend on one single player will bring you only so far.
Therefore I hope that Ibra is only the beginning of a strategy that sees more mentaly strong players coming in to lead the others. If we don't, well, then I agree that we are going to have a problem sooner or later. But we have to start somewhere somehow. And Ibra IMO is the perfect starting point.