Hearing various analysts as well as Indian posters here mention Shami's absence as being so damaging to India in this series, I finally checked his stats in Australia, expecting him to average sub 25 or so.
But to my surprise, he has average stats there; 31 wickets in 8 matches at 32. Siraj has similar stats (a slightly better average and ER in 7 matches).
So it doesn't seem his presence would have made much of a difference. Aakash in his absence has done a pretty decent job; has just been unlucky, going past edge a dozen of times in two tests.
From my memory, he always has been a very good bowler in Indian conditions, blowing teams away with his reverse swing bowling. Also remember him causing problems in SA.
Other than that he has struggled In England and Australia.