AC Milan is like downgrade their squad for letting their good players to leave. They already lost Ibrahimovic, Giroud will retire soon, they only have Hernandez, Leao, Tomori and Calabria, the other are just to complete the squad.
Arsenal sign Declan Rice for 105 Million Euros, while the cost of Newcastle to sign Tonali is only half of it, I think both of them are good players, but Rice is overpriced and overestimate.
Well, football clubs need to survive and thats just what AC Milan are trying to do; if you can't get funds from the clubs revenue etc; you get funds from the clubsides pool of talent; With Tonali, AC Milan has made tremendous profits and can reshape their squad if they spend wisely; Getting Lukaku on loan is part of AC Milan rebuild process too.
And yes, Rice is a very quality midfielder; good fee too (thanks to West Ham owner quality negotiation skills).
Tony deserved it. Newcastle United will fight in UCL next year and they want to enter UCL with a worthy squad. Tonali, for whom they paid 70 million Euros for his testimonial, becomes a midfielder for Newcastle that has been considered for many years.