I think there are two questions here.
1. If the appointment of Atif Mian is going to be acceptable to general public because of his deviation from the mainstream religious beliefs? and
2. If Atif Mian can deliver what he is hired by Imran Khan to do?
More than likely the answer to 1. will be NO because of the immense public pressure, which will automatically result in a NO answer on 2nd question.
If the answer to 1. somehow turns out to be YES, then question 2 may become a YES or MAYBE.
Realistically Atif maybe able to get IMF loan which will solve country's short term financial problem, though long-term solution will always be in developing natural resources, collection of taxes from those at the higher income level, and increasing exports of locally manufactured goods. This can only happen if the locally manufactured goods can compete with in the international market - better quality at competitive prices.