I agree that form is not always appear. A player can play very well but he will lose form at some point and regain that form again. But I have no complaints about the form in the case of Pakistan. What I would say is that their top order is good but neither middle nor lower is reliable. We saw in the Asia Cup how they lost to Sri Lanka in the final. Again they did the same with Zimbabwe in the World Cup. Without any doubt i can say that they have weaknesses in this point. They can fight against hard team and also lose unexpectedly against weak team as well.
What they need is some good pace bowling all rounders in the middle order. Two decades back they had players such as Azhar Mahmood and Abdul Razzaq. But ever since the retirement of these players, they have been dependent on spin-bowling allrounders such as Shoaib Malik and Mohammed Hafeez. Some of the pacers, such as Shaheen Shah Afridi and Haris Rauf can bat a bit, but they can't be considered as all rounders. This is one component where Pakistan have been lagging. They need someone like Cameroon Green of Australia.