Saqlain as a HC might be a premature call. I say let him do what he does best, that is to be spin specialist. We have a huge pool of spinners and Saqlain can work in the national/academy levels. In the national level, he will polish the spinners and on academy level he will groom them more slowly and nurture the talent. McInnes will oversee batting and other things while Saqlain can work with the spinners.
Saqlain also has tremendous understanding and experience of the game which SJ don't have. I assume he plays a big decision making role in the management. He also has great appreciation of the local players and once tweeted about the massive talent in the academy level.