Now to be fair, I will expect you to be fair :
See you are asking for the consistency of Asad Shafiq in-between those 7 test matches, but can I ask what Sami Aslam has done in his 13 Test matches, yet scored not a single century. What Babar did in his 11 test matches, yet not a single century.
Regarding Asad Shafiq !! Well he bats at lower numbers, No.6, he comes when the bulk of the batting fails in pathetic style, you should know that playing against Australia in Australia is something that needs a highest quality of cricket, its not something playing the lowest ranking teams like Srilanka in UAE.
His both innings (in which he made centuries) came when the team was about to loose whether, no other player in the current test team dared to make century in such time when the team was about to give, making century against Australia in Australia and thats too in a very crises situation, is something not too many visiting players do in Australia. It describes Asad's fighting spirit. Asad's spirit of resistance and his ability to stand til last.
Now tell me we what your dearest players did after playing too many test innings, that is too as an opener ??? .... (Sami Aslam). His average is 31 and strike rate is 39.. number of centuries NIL .... Yet WOW What a talent !! OMG