Pakistan just needs to get its combination right. In my opinion, on a priority basis, we need to get rid of Fahim Ashraf and Hasnian. Hasnain though can be a long term asset, he needs some investment of time and resources however Its a huge gamble picking him over Aamir and trying an experiment in the World Cup ahead. As far as Fahim Ashraf is concerned, He has always been an ordinary cricketer thus far, I don't consider him an international material. If he gets his batting right he can be useful but as far as his bowling is concerned. He is below average internationally no matter how many wickets he takes in PSL and domestic.
We need to have Aamir and Junaid back in the side. Those who are ruling our Pakistan so early in WC. Boy, Its a long tournament ahead and for Pakistan, it's good for them if they lose the initial matches because they are always dangerous when they are hurt. They just need a balanced combination and believe me it'd be extremely difficult for other teams to beat them.
I'd love to comment here on the views that on CT 2017 it was more luck than performance. Closing your eyes won't hide the reality, we all know that Pakistan won CT with their superb bowling performance. So there are plenty of matches ahead. However, If Inzy tried to stick with Hasnain and Fahim, then Pakistan chances would be slimmer due to below average bowling combination.
In an ideal situation, We can have Aamir and Junaid opening the attack with Hasan Ali and Shahdab/Shaheen coming in between overs. In batting, watch out for Babar Azam and we also need Fakhar Zaman to click to pile up bigger scores.
For today's match, England deserves the full credit as well, Pakistan was 20 to 25 runs short when Babar and Haris missed the plot, England grabbed that opportunity.