I wouldn't call this flying blind. I think there were a number of notable performances by players in this series that showed they are capable of hanging at the T20I level. Salman Ali Agha, Hassan Nawaz, Mohammad Haris, Sufiyan Muqeem, Haris Rauf, Abrar Ahmed, Shadab Khan, Abdul Samad, Irfan Khan all showed something. The next thing you do is try to add players like Saim Ayub, Fakhar Zaman, Haider Ali and other guys who perform in the PSL into the mix, identify what roles they will play, and try and see what you best combination looks like. Not all 16-17 players are going to be match-winners, so obviously some will have to be discarded. But this should be a long-term trial-and-error strategy spread out over multiple bilateral series.
That should be the plan, I don't see what's so hard to follow or understand?