Pakistan's approach did not work ultimately because they couldn't really find a bowler to score runs off. In England, they would see off Broad, Anderson, score off Finn and Ali and then ultimately start scoring off Broad and Anderson too. Here they just couldn't find that break. Astle just bowled 4 overs. This is why, despite seeing off the new ball on both innings, their strategy failed big time.
Azhar also has to shoulder some of the blame here. This has been the most frustrating thing about his growth as a batsman. He just doesn't want to play the senior batsman. This is what his stunting his growth and ultimately hurting Pakistani batting. He has to figure out ways to score runs and be the leading batsman when batting with Sami, Babar and sometimes even YK, Misbah when they are new at the crease. This is what YK excels in when he gets set, this is perhaps his best quality as a batsman more than his sweep shots and defence and all that. It's his ability to figure out ways to score runs no matter what's happening at the other end, no matter if he is batting with the tail or a top order batsman, and that in turn is why he has been part of so many successful partnerships for Pakistan.
Azhar is still playing like the youngster who has come into the side and is barely 1 year old in test cricket, and happy for the senior batsmen to score the runs while he holds up one end. Well you're the senior batsman now.