Gary Neville has just ripped into both teams.
Problem is Rodgers and Wenger are both too philosophical about football and are stubborn to boot (we won't change how we play for anybody). Its all style, attack, attack, technique, pace and movement. Fair enough, but that just means you're likely a leaky basket for goals at the back.
They try to be sentimentally Barcelona-esque...forgetting that even Barca in their prime knew how to defend.
Wenger succeeded initially because he had David Dein, and consequently, self-sufficient players/leaders who took care of the finer details. Rodgers succeeded because he had a lethal front 3 and fewer matches. Plus Chelsea's team was incomplete, United were in disarray, and City had a slow start.
Mourinho and Fergie have always been ruthlessly pragmatic, hence their success. They know its delicate balance. You need a strong spine plus width.
Liverpool and Arsenal need a spine. United need a rearguard. Until then...it'll be the same old story.