Agreed, but it's not the squad, it's the culture. If you read about the Hundred Monkey effect, you will know what I'm talking about. In case you didn't it was basically an observation where a new behaviour spreads through a group of monkey, despite the originator not being there anymore.
Both Fergie and Cruyff when they stepped into their roles had to change the established culture(drinking at Man Utd and being victims at Barca). We have a culture of over entitled brats as things stand.
How many times did we have new players join in and then within 6 months they start losing their spark? Just look at Bruno. When he joined he looked like this determined WC player willing to uphold standards and his team mates accountable. Now look at him now: a shell of himself that constantly complains about everything. For some people the environment is too big of a hurdle to handle.
Ronaldo is the exception. Unlike most players, he doesn't let the environment dictate how he should feel, but rather the opposite. Hence the strife in the dressing room, because his presence is challenging the established status quo.
The biggest challenge ETH will face isn't the board or transfers or playing styles... it will be to completely uprooting this toxic over entitled environment and replace it with a meritocratic one.