People won't like to hear this nor will they accept it but Tyson Fury would make easy work of Ali. Ali couldnt deal with someone this big and this good in the modern era.
I'd take Joshua over him. That raw power will put fury on his ass. AJ has way more power than anyone he has ever faced. And a few of them have dropped him. Fury doesn't have a great deal of ko power. So if he gases,he regains his energy and gets a win.