Managers like Allegri and Simeone have done incredible jobs at their respective clubs and are legends for sure.
The problem is their brand of football isn't that pleasing to watch IMO. I couldn't stomach watching more low-quality of football every weekend. And in Allegri's case in particular, I still question how he would do at a club that has the financial restrictions we do in a league that is as competitive as ours.
Stylistically, Ten Haag's youthful Ajax team have impressed me more than any Juventus side has in the last 5 years.
I want us to win games and I want us to win trophies, but I want us to do so with an attacking philosophy. Having an attacking philosophy and having a good defence aren't mutually exclusive things, as we have seen in Liverpool's case.
My fear is a manager with the footballing principles of Allegri would hinder the attacking potential in the type of team we are looking to build.
Also, there is a Juventus blogger who wrote this piece for ESPN a couple of years ago and this section struck me:
Much like Pep Guardiola has learnt with Manchester City, it is difficult to implement tactical ideas when the team you are training is susceptible to mental fragility. Allegri is not a man who creates superstars, he refines them, but he needs to oversee a side that is already mentally tough
If this is the case, then he wouldn't be much good for us unless we already have a ready-made side.