Trent was captain of Liverpool youth teams and England produced a number of quality fullbacks recently. Also Liverpools defensive stability came after Van Djik and Alisson. For me, at the end of the day it's the players who make the difference, the coach needs to have an eye of who the best players are, suited to style and rest of the team.
I am usually aligned with Allegri on his picks expect for his call on Cancelo. This year though imo Allegri was pretty off, if he really was hoping for 10 goals from Rabiot/McKennie or counting on Morata for the goals.